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135 Science and Nature Trivia Questions and Answers

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Easy Science and Nature Trivia Questions

  1. Which evolutionary process can make helpful inherited traits more common?

    Natural selection

    Natural selection can make helpful inherited traits more common because individuals with those traits tend to survive and reproduce more, passing them to their offspring. Over many generations, this process can produce adaptations such as camouflage.

    Easy · Also offered: Genetic drift, Gene flow, Genetic recombination · Source: naturalhistory.si.edu

  2. What is the chemical symbol for silver?

    Ag

    Silver is represented by Ag, derived from the Latin word argentum.

    Easy · Also offered: Al, Ar, As · Source: Royal Society of Chemistry, Periodic Table: Silver

  3. Which physicist developed the theory of relativity?

    Albert Einstein

    Albert Einstein developed the special and general theories of relativity.

    Easy · Also offered: Niels Bohr, Max Planck, Erwin Schrödinger · Source: Encyclopaedia Britannica

  4. The SI unit of electric potential honours which Italian scientist?

    Alessandro Volta

    The volt, the SI unit of electric potential, is named for Alessandro Volta.

    Easy · Also offered: Enrico Fermi, Guglielmo Marconi, Galileo Galilei · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  5. What is the name for the larval stage of a frog?

    Tadpole

    A tadpole typically begins life with gills and a tail, then develops lungs and legs during metamorphosis. Its adult form is adapted for life on land as well as in water.

    Easy · Also offered: Caterpillar, Nymph, Pupa · Source: Smithsonian National Zoo: Frog life cycle

  6. The centigrade temperature scale honours which Swedish scientist?

    Anders Celsius

    The Celsius scale is named after Anders Celsius, who proposed it in 1742.

    Easy · Also offered: Carl Linnaeus, Svante Arrhenius, Alfred Nobel · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  7. Antibiotics are medicines designed primarily to treat infections caused by what?

    Bacteria

    Antibiotics are medicines designed to treat infections caused by bacteria. They do not work against viruses, which is why they cannot treat illnesses such as colds or the flu.

    Easy · Also offered: Viruses, Fungi, Protozoa · Source: CDC: Antibiotic use and antimicrobial resistance

  8. Which ancient Greek formulated the buoyancy principle?

    Archimedes

    Archimedes formulated the principle explaining buoyant force in fluids.

    Easy · Also offered: Aristotle, Pythagoras, Hippocrates · Source: Encyclopaedia Britannica

  9. What does an element's atomic number tell you?

    Number of protons

    An element's atomic number is the number of protons in each atom's nucleus.

    Easy · Also offered: Number of neutrons, Number of electron shells, Number of particles in the nucleus · Source: U.S. Department of Energy

  10. What stream of charged particles from the Sun helps cause auroras?

    The solar wind

    The solar wind blows steadily outward from the Sun. Earth's magnetic field funnels some of those particles down towards the poles, where they collide with atmospheric gases and make them glow, most often the green of excited oxygen.

    Easy · Also offered: The solar corona, Solar ultraviolet light, The Sun's magnetic field · Source: NASA Science, Auroras (direct source)

  11. What is the chemical symbol for calcium?

    Ca

    Calcium is Ca. It is the metal locked into the mineral of bones and teeth, and into limestone, chalk and seashells.

    Easy · Also offered: Cd, Ce, Cl · Source: Royal Society of Chemistry, Periodic Table: Calcium

  12. Why do stars appear to twinkle when viewed from Earth?

    Atmospheric turbulence refracts starlight

    Moving pockets of air at different temperatures refract starlight in changing ways. Planets usually twinkle less because their apparent disks average out some of that variation.

    Easy · Also offered: Intrinsic pulsation changes starlight, Solar-wind interference alters starlight, Earth's rotation shifts starlight · Source: NASA: Why do stars twinkle?

  13. Which chemical symbol represents iron?

    Fe

    Iron's symbol Fe comes from its Latin name, ferrum. Iron is the main structural metal in steel and is also essential for hemoglobin in red blood cells.

    Easy · Also offered: F, Ir, In · Source: Royal Society of Chemistry: Iron

  14. What thin, wispy cloud forms high in the atmosphere?

    cirrus

    Cirrus clouds are thin, wispy clouds found at high altitudes.

    Easy · Also offered: cumulus, stratus, cumulonimbus · Source: NOAA National Weather Service

  15. Why does a person's breath become visible outdoors on a cold day?

    Condensation

    Water vapor in exhaled air condenses into tiny droplets in the cold air.

    Easy · Also offered: Evaporation, Sublimation, Crystallization · Source: National Weather Service, Why Can I See My Breath When It's Cold?

  16. What process makes warmer, less-dense air rise while cooler air sinks?

    convection

    This circulation drives everyday weather, from sea breezes that form as coastal air heats unevenly to the towering clouds inside a thunderstorm. The same principle, on a vastly slower scale, moves molten rock in Earth's mantle and helps drive the motion of tectonic plates.

    Easy · Also offered: conduction, radiation, evaporation · Source: NASA Science: AOS Glossary

  17. What causes the Coriolis effect?

    Earth's rotation

    It deflects moving air and water to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, which is why hurricanes spin counterclockwise north of the equator and clockwise south of it. The effect is zero at the equator and strongest near the poles.

    Easy · Also offered: The Moon's gravitational pull, Earth's magnetic field, Differences in air pressure · Source: US National Weather Service

  18. What is the chemical symbol for copper?

    Cu

    Copper is represented by Cu, derived from the Latin word cuprum.

    Easy · Also offered: Ca, Co, Cr · Source: Royal Society of Chemistry, Periodic Table: Copper

  19. What tall cloud type is commonly linked with thunderstorms?

    cumulonimbus

    Cumulonimbus clouds are tall, vertically developed clouds associated with thunderstorms.

    Easy · Also offered: nimbostratus, altocumulus, stratocumulus · Source: NOAA National Weather Service

  20. What puffy, cotton-like cloud often appears in fair weather?

    cumulus

    Cumulus clouds are rounded and puffy and commonly form in fair weather.

    Easy · Also offered: cirrus, stratus, cumulonimbus · Source: NOAA National Weather Service

  21. Who wrote the landmark book On the Origin of Species?

    Charles Darwin

    Darwin's book presented evolution by natural selection as a mechanism for species change. Alfred Russel Wallace independently developed a similar idea and helped prompt Darwin to publish.

    Easy · Also offered: Alfred Wallace, Gregor Mendel, Carl Linnaeus · Source: Natural History Museum: Charles Darwin

  22. Which biological group commonly acts as a decomposer in ecosystems?

    Fungi

    Fungi are widely identified as decomposers in ecosystems, including forests, where they break down organic material.

    Easy · Also offered: Protists, Arthropods, Mollusks · Source: fs.usda.gov

  23. What does DNA stand for?

    Deoxyribonucleic acid

    Deoxyribonucleic acid carries genetic instructions in nearly all living organisms, named for the deoxyribose sugar in its backbone.

    Easy · Also offered: Dinucleic acid, Deoxyribose nucleic amine, Double nucleic acid · Source: National Human Genome Research Institute

  24. What causes the different colors in a typical fireworks display?

    Different metal salts

    Heated metal salts emit characteristic wavelengths of visible light.

    Easy · Also offered: Different oxidizing agents, Different fuel mixtures, Different binders · Source: American Chemical Society, The Chemistry of Fireworks

  25. About when did the non-avian dinosaurs go extinct?

    About 66 million years ago

    The extinction occurred at the boundary between the Cretaceous and Paleogene periods. Evidence points to the Chicxulub asteroid impact as the main trigger, alongside severe environmental disruption.

    Easy · Also offered: About 30 million years ago, About 50 million years ago, About 100 million years ago · Source: Smithsonian National Museum of Natural History: Mass extinction of non-avian dinosaurs

  26. What molecule carries hereditary information in most living organisms?

    DNA

    DNA holds the instructions for building an organism's proteins, written in a four-letter chemical alphabet. It is copied every time a cell divides and passed from parent to offspring, which is why traits run in families.

    Easy · Also offered: ATP, Starch, Chlorophyll · Source: National Human Genome Research Institute

  27. Which desert is commonly cited as the driest nonpolar desert on Earth?

    Atacama Desert

    Parts of Chile's Atacama receive less than a millimeter of rain in an average year. Its dryness results from cold offshore water, subtropical high pressure, and rain-shadow effects from the Andes.

    Easy · Also offered: Sahara Desert, Gobi Desert, Kalahari Desert · Source: NASA Science and NOAA reference material

  28. What is dry ice?

    Solid carbon dioxide

    Dry ice is the solid form of carbon dioxide rather than frozen water.

    Easy · Also offered: Frozen water, Solid nitrogen, Frozen oxygen · Source: NASA Jet Propulsion Laboratory Education

  29. What causes seasonal changes?

    Earth's axial tilt

    Earth's axial tilt changes the angle and duration of sunlight received by each hemisphere over the year.

    Easy · Also offered: Earth's orbital distance, Earth's rotation, Changes in the Sun's output · Source: NASA Science: Earth

  30. What role does a green plant usually play in a food chain?

    A primary producer

    Green plants produce organic food using light energy, so they form the producer level of food chains.

    Easy · Also offered: A nutrient decomposer, A first-level consumer, A feeding parasite · Source: US National Park Service

  31. What force provides the inward acceleration for a planet orbiting the Sun?

    Gravity

    Gravity attracts masses and provides the inward acceleration that maintains planetary orbits around the Sun.

    Easy · Also offered: Electromagnetism, Strong nuclear force, Weak nuclear force · Source: NASA Science: Gravity

  32. Which fossil fuel formed mainly from ancient swamp plants?

    Coal

    Coal formed from plant material buried in oxygen-poor swamps and transformed by heat and pressure over millions of years. Petroleum and natural gas mostly formed from ancient microscopic marine organisms.

    Easy · Also offered: Petroleum, Natural gas, Oil shale · Source: USGS: Coal explained

  33. Paleontologists and archaeologists are often mixed up. What does a paleontologist study?

    Fossils of ancient life

    Paleontology reconstructs life from the distant past through fossils, which is why dinosaurs belong to paleontologists rather than archaeologists. Archaeology studies the human past through what people made and built, stratigraphy reads rock layers, and ancient scripts fall to epigraphy.

    Easy · Also offered: The objects and buildings people left behind, The layers and structure of rock, Ancient written languages · Source: University of California Museum of Paleontology

  34. Which is the hardest naturally occurring mineral on the Mohs scale?

    Diamond

    Diamond ranks 10, the highest value on the Mohs hardness scale. Its carbon atoms are locked into a very strong three-dimensional crystal lattice.

    Easy · Also offered: Quartz, Calcite, Gypsum · Source: USGS: Mohs hardness scale

  35. What is the relatively calm center of a hurricane called?

    The eye

    The eye is the central region of a mature tropical cyclone, surrounded by the eyewall's strongest winds.

    Easy · Also offered: The wall, The tail, The trough · Source: nhc.noaa.gov

  36. What term describes a non-native organism that spreads through a new habitat and damages it?

    An invasive species

    An invasive species is one carried outside its native range that establishes itself, spreads and causes ecological or economic harm. Introduced species that settle in without doing damage are called naturalized instead.

    Easy · Also offered: A naturalized species, A feral species, A pest species · Source: invasivespeciesinfo.gov

  37. The SI unit of force honours which English scientist?

    Isaac Newton

    The newton, the SI unit of force, was named after Isaac Newton.

    Easy · Also offered: Michael Faraday, James Prescott Joule, Stephen Hawking · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  38. Why does ice float in a glass of water?

    Its density is lower than the surrounding liquid's.

    Ice's open crystal structure makes it less dense than liquid water.

    Easy · Also offered: Its temperature is higher than the surrounding liquid's., Its heat capacity is lower than the surrounding liquid's., Its surface tension is higher than the surrounding liquid's. · Source: OpenStax Chemistry 2e

  39. The SI unit of energy honours which British physicist?

    James Prescott Joule

    The joule is named for James Prescott Joule, the Salford brewer's son who showed that heat and mechanical work are interchangeable by churning water with a falling-weight paddle wheel and measuring how much it warmed.

    Easy · Also offered: George Gabriel Stokes, William Henry Bragg, John William Strutt · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  40. The SI unit of power honours which Scottish scientist?

    James Watt

    The watt was named after James Watt, the Scottish engineer.

    Easy · Also offered: James Clerk Maxwell, Lord Kelvin, David Brewster · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  41. What is the chemical symbol for potassium?

    K

    Potassium is K, from kalium, its Latin name, taken in turn from the Arabic word for the plant ash it was first extracted from. P belongs to phosphorus.

    Easy · Also offered: P, Na, Ca · Source: Royal Society of Chemistry, Periodic Table: Potassium

  42. What travels fastest through air?

    Light

    Light crosses air at roughly 300,000 kilometres per second; sound manages about 343 metres per second at room temperature, close to a million times slower. That gap is why a lightning flash is seen well before the thunder arrives, and why counting the seconds between them tells you how far away the strike was.

    Easy · Also offered: Sound, A rifle bullet, A jet aircraft · Source: NASA Science

  43. What kind of measurement is a light-year?

    Distance

    A light-year is the distance light travels in one year, about 9.46 trillion kilometres. Astronomers use it to describe distances between stars and other objects.

    Easy · Also offered: Time, Brightness, Temperature · Source: NASA Science: Cosmic distances

  44. What is lightning?

    An electrical discharge

    Lightning is a giant electrical discharge in the atmosphere, often within or between storm clouds or to the ground.

    Easy · Also offered: A shock wave in the air, A burst of magnetic flux, A column of superheated rain · Source: US National Weather Service

  45. Which metal is widely used for electrical wiring?

    Copper

    Copper conducts electricity nearly as well as silver at a tiny fraction of the price, and it is soft enough to be drawn into long thin wire without snapping. That combination is why it ended up inside almost every cable in a house.

    Easy · Also offered: Gold, Silver, Iron · Source: US Geological Survey

  46. What is molten rock called while it is still beneath Earth's surface?

    Magma

    Molten rock underground is called magma; once it erupts onto the surface, it is called lava. Magma can cool underground to form intrusive igneous rock.

    Easy · Also offered: Lava, Ash, Pumice · Source: USGS: Volcano hazards glossary

  47. Which object's gravity has the largest effect on Earth's ocean tides?

    Moon

    The Moon is much closer to Earth than the Sun, so its tidal effect is stronger despite the Sun's greater mass. The Sun still contributes to tides, producing spring and neap tide patterns with the Moon.

    Easy · Also offered: The Sun, Jupiter, Venus · Source: NASA Science and NOAA reference material

  48. Mushrooms belong to which biological kingdom?

    Fungi

    Mushrooms are the visible reproductive structures of certain fungi. Fungi obtain nutrients by breaking down and absorbing organic matter rather than by photosynthesis.

    Easy · Also offered: Plants, Animals, Protists · Source: USDA Forest Service: Fungi

  49. Which science studies mushrooms, molds and yeasts?

    Mycology

    Mycology is the study of fungi, from the Greek mykes for mushroom. Fungi form a kingdom of their own and are genetically closer to animals than to plants: they do not photosynthesise, but absorb nutrients from whatever they are growing on.

    Easy · Also offered: Botany, Bacteriology, Virology · Source: Encyclopaedia Britannica, mycology

  50. What is the chemical symbol for sodium?

    Na

    Sodium is represented by Na, derived from the Latin word natrium.

    Easy · Also offered: Ne, Ni, Nb · Source: Royal Society of Chemistry, Periodic Table: Sodium

  51. What type of cell carries electrical signals through the nervous system?

    Neuron

    Neurons communicate using electrical impulses and chemical signals at junctions called synapses. Their long extensions can carry messages over substantial distances in the body.

    Easy · Also offered: Glial cell, Hepatocyte, Fibroblast · Source: National Institute of Neurological Disorders and Stroke: Neurons

  52. How many astronauts walked on the Moon during the Apollo programme?

    12

    They came from six landing missions between 1969 and 1972. Neil Armstrong was the first to step onto the surface, during Apollo 11, and Gene Cernan closed out the programme as the last, on Apollo 17.

    Easy · Also offered: 6, 8, 24 · Source: NASA: Apollo missions

  53. How many hearts does an octopus have?

    3

    An octopus has three hearts: two pump blood to its gills and one pumps it around the body.

    Easy · Also offered: 1, 5, 8 · Source: Smithsonian Ocean: Octopus

  54. What chemical process gives exposed iron its familiar reddish coating?

    Oxidation

    The reaction needs both oxygen and water to proceed, producing hydrated iron oxide. Unlike the tight oxide layer that protects metals such as aluminum, rust is porous and flakes away, constantly exposing fresh metal underneath so the process never stops on its own.

    Easy · Also offered: Reduction, Hydrolysis, Neutralization · Source: Royal Society of Chemistry, Rusting Iron

  55. Which type of radiation is absorbed especially strongly by the ozone layer?

    Ultraviolet radiation

    Stratospheric ozone absorbs much of the Sun's harmful ultraviolet radiation. This shielding reduces the amount of DNA-damaging UV that reaches Earth's surface.

    Easy · Also offered: Infrared radiation, Microwave radiation, Radio radiation · Source: NASA Science: Earth

  56. How many oxygen atoms are in one ozone molecule?

    Three

    Ozone is O3, meaning each molecule contains three oxygen atoms.

    Easy · Also offered: One, Two, Four · Source: epa.gov

  57. Which gas do plants take in for photosynthesis?

    Carbon dioxide

    Plants take in carbon dioxide during photosynthesis and use light energy to make sugars, releasing oxygen as a byproduct.

    Easy · Also offered: Oxygen gas, Nitrogen gas, Water vapor · Source: earthobservatory.nasa.gov

  58. Which planet is closest to the Sun?

    Mercury

    Mercury orbits the Sun at an average distance of about 58 million kilometres. Its year lasts only 88 Earth days.

    Easy · Also offered: Venus, Earth, Mars · Source: NASA Science: Mercury

  59. Where do most plants get the nitrogen they need?

    From the soil, through their roots

    Air is about 78 per cent nitrogen, but plants cannot use the gas directly; its triple bond is too strong to break. They take nitrogen up through their roots as nitrate and ammonium dissolved in soil water. Legumes such as peas, beans and clover are the exception, housing bacteria in root nodules that convert nitrogen gas into a usable form.

    Easy · Also offered: From the air, through their leaves; From the carbon dioxide they take in; From rainwater falling on them · Source: USDA: Plant nutrients

  60. Which gas do green plants release during photosynthesis?

    Oxygen

    Photosynthesis uses light energy to split water molecules apart. The hydrogen goes into building sugar out of carbon dioxide, and the leftover oxygen is released into the air. Nearly all the oxygen we breathe came out of that reaction.

    Easy · Also offered: Nitrogen, Helium, Methane · Source: NASA Earth Observatory

  61. What state of matter makes up most of the Sun?

    Plasma

    The Sun is made mostly of plasma, a hot ionized state of matter.

    Easy · Also offered: Liquid, Solid, Gas · Source: NASA Science

  62. In a flowering plant, pollination transfers pollen from where to where?

    From anther to stigma

    Pollination transfers pollen from the anther, the pollen-producing part of a flower, to the stigma. The pollen can then germinate on the stigma and grow a tube toward the ovule for fertilization.

    Easy · Also offered: From filament to style, From anther to ovule, From filament to ovary · Source: U.S. Forest Service: Pollination

  63. What is the primary pigment plants use to capture sunlight?

    Chlorophyll

    Chlorophyll absorbs blue and red wavelengths especially well and reflects more green light, making many leaves appear green. It is embedded in the photosynthetic membranes of chloroplasts.

    Easy · Also offered: Xanthophyll, Carotenoid, Anthocyanin · Source: U.S. Forest Service: Chlorophyll and photosynthesis

  64. What is the approximate pH of pure water at 25 degrees Celsius?

    7

    A pH of 7 is considered neutral at 25 degrees Celsius because the concentrations of hydrogen and hydroxide ions are equal. Temperature changes can slightly shift the neutral pH.

    Easy · Also offered: 5, 9, 11 · Source: USGS: pH and water

  65. Which planet is commonly called the Red Planet?

    Mars

    Mars looks rusty because it is rusty: its surface dust is rich in iron oxide, which coats the ground and hangs in the thin atmosphere. That blood-coloured tint in the night sky is why the Romans named the planet after their god of war.

    Easy · Also offered: Venus, Jupiter, Neptune · Source: NASA Science

  66. Why does a straw appear kinked at the surface of a drink?

    Refraction of light

    Light changes direction as it passes between air and the drink.

    Easy · Also offered: Reflection of light, Diffraction of light, Polarization of light · Source: OpenStax University Physics

  67. What does RNA stand for?

    Ribonucleic acid

    Ribonucleic acid differs from DNA in using ribose rather than deoxyribose, and uracil in place of thymine.

    Easy · Also offered: Ribose nitrogen acid, Replicating nucleic acid, Ribonucleotide amine · Source: National Human Genome Research Institute

  68. What type of rock forms when magma or lava cools and solidifies?

    Igneous rock

    Igneous rocks form either underground from slowly cooling magma or at the surface from rapidly cooling lava. Granite and basalt are common examples.

    Easy · Also offered: Sedimentary rock, Metamorphic rock, Organic rock · Source: USGS: Igneous rocks

  69. What does a control group provide in an experiment?

    A baseline for comparison

    A control group gives researchers a reference point for judging the effects of the tested variable.

    Easy · Also offered: A check on the study's design, A test of the research hypothesis, A measure of the observed outcome · Source: nigms.nih.gov

  70. Beachcombers who take the hobby seriously call it conchology. What are they collecting?

    Seashells

    Conchology is the collecting and study of mollusc shells, from the Greek konkhe, meaning mussel or shell. The related science of malacology studies the soft-bodied animals that build the shells.

    Easy · Also offered: Sea glass, Fossilized sharks' teeth, Driftwood · Source: Merriam-Webster Dictionary, conchology

  71. What is the SI unit of electric current?

    Ampere

    The ampere measures the flow of electric charge. Volts measure potential difference, ohms measure resistance, and watts measure power.

    Easy · Also offered: Volt, Ohm, Watt · Source: NIST: SI units: ampere

  72. What are the especially high and low tides that occur when the Sun and Moon line up called?

    Spring tides

    At new and full moon the Sun and Moon pull along the same line, their tidal forces add together, and the gap between high and low water is at its greatest. The name comes from water springing up, not from the season. A week later the two pull at right angles and the range is at its smallest, giving a neap tide.

    Easy · Also offered: Neap tides, King tides, Storm tides · Source: NOAA NESDIS

  73. What flat, gray cloud layer can cover much of the sky?

    stratus

    Stratus clouds form broad, flat layers that can make the sky look gray.

    Easy · Also offered: cirrus, cumulus, cumulonimbus · Source: NOAA National Weather Service

  74. What is the world's tallest tree species?

    Coast redwood tree

    Coast redwoods can exceed 370 feet and thrive in the foggy coastal climate of northern California. Giant sequoias are generally more massive, but coast redwoods are taller.

    Easy · Also offered: Douglas fir tree, Sitka spruce tree, Giant sequoia tree · Source: National Park Service: Coast redwoods

  75. What is the main geological cause of most earthquakes?

    Plate movement

    Most earthquakes occur when stress built up along faults is released as tectonic plates move. Volcanic activity and human activity can also trigger some earthquakes.

    Easy · Also offered: Volcanic activity, Landslide collapse, Meteor impacts · Source: U.S. Geological Survey: What is an earthquake and what causes them?

  76. The aurora borealis is named after the Roman goddess of what?

    The dawn

    Aurora was the Roman goddess of dawn, and borealis comes from Boreas, the Greek north wind. The name reads as 'dawn of the north'.

    Easy · Also offered: The moon, Winter, The night sky · Source: Encyclopaedia Britannica, 'aurora'

  77. The metal titanium is named after which figures from Greek myth?

    The Titans

    Martin Heinrich Klaproth named the element in 1795 after the Titans, the older generation of gods known for their strength.

    Easy · Also offered: The Olympians, The Cyclopes, The Giants · Source: Royal Society of Chemistry, Periodic Table

  78. What supplies the main energy that powers a hurricane?

    Warm ocean water

    A hurricane runs on heat drawn from ocean water of roughly 26 degrees Celsius or warmer. Evaporation lifts that heat into the storm, where it is released as the vapour condenses. Cut off the warm water, by landfall or by moving over a cooler sea, and the storm weakens quickly.

    Easy · Also offered: The Earth's rotation, Warm land surfaces, Strong upper-level winds · Source: NOAA National Hurricane Center: Tropical cyclone formation

  79. In which layer of Earth's atmosphere does most weather occur?

    Troposphere

    The troposphere is the lowest atmospheric layer and contains most of the atmosphere's water vapor. Rising and sinking air in this layer drives clouds, winds, and storms.

    Easy · Also offered: Stratosphere, Mesosphere, Thermosphere · Source: NOAA: Layers of the atmosphere

  80. At sea level, at what temperature does water boil on the Celsius scale?

    100 degrees Celsius

    At standard atmospheric pressure, water boils at 100 degrees Celsius. The boiling point decreases at higher elevations because air pressure is lower.

    Easy · Also offered: 90 degrees Celsius, 110 degrees Celsius, 120 degrees Celsius · Source: NIST: Water properties

  81. Which chemical formula represents water?

    H2O

    Each water molecule contains two hydrogen atoms bonded to one oxygen atom. The bent shape of the molecule gives water many of its unusual properties.

    Easy · Also offered: CO2, O2, NaCl · Source: USGS: Water properties

  82. What water-cycle process is associated with dew forming overnight?

    Condensation

    Dew forms when water vapor in the air cools and condenses into liquid water on cooler surfaces overnight. This usually happens when surfaces reach the dew point, the temperature at which the air becomes saturated.

    Easy · Also offered: Precipitation, Infiltration, Transpiration · Source: U.S. Geological Survey

  83. Which water-cycle process turns liquid water at a lake's surface into a gas?

    Evaporation

    It happens well below boiling point because only the fastest-moving surface molecules gain enough energy to escape into the air as vapor. That is also why it cools whatever liquid is left behind, the same principle that makes sweat effective at cooling skin.

    Easy · Also offered: Transpiration, Sublimation, Precipitation · Source: U.S. Geological Survey

  84. Water is unusual because its solid form floats on its liquid. Why?

    Ice is less dense than liquid water

    When water freezes, hydrogen bonds lock its molecules into an open hexagonal lattice with more empty space than in the liquid, so the same mass takes up about 9 percent more volume as ice. Very few other liquids expand rather than contract as they solidify.

    Easy · Also offered: Ice traps air bubbles as it forms, Ice is colder than the water beneath it, Ice has a lower surface tension · Source: U.S. Geological Survey

  85. What is a tornado-like vortex over a lake or sea called?

    waterspout

    A waterspout is a rotating column of air that forms over a lake or sea, often drawing up water spray. Some waterspouts are tornadoes over water, while others form in fair weather beneath developing clouds.

    Easy · Also offered: steam devil, funnel cloud, gustnado · Source: NOAA National Weather Service

Medium Science and Nature Trivia Questions

  1. The SI unit of electric current honours which French scientist?

    André-Marie Ampère

    The ampere, the SI unit of electric current, honours André-Marie Ampère.

    Medium · Also offered: Henri Becquerel, Louis de Broglie, Jean-Baptiste Lamarck · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  2. Under ideal conditions, roughly how much can the fastest-growing bamboo add in a single day?

    About 3 feet

    The quickest bamboos can put on close to a metre, about three feet, in twenty-four hours, which makes them the fastest-growing plants on Earth. The shoot manages it by stretching cells that are already formed rather than building new ones.

    Medium · Also offered: About 6 inches, About 1 foot, About 6 feet · Source: Royal Botanic Gardens, Kew: Bamboo

  3. The SI unit of pressure honours which French scientist?

    Blaise Pascal

    The pascal, the SI unit of pressure, bears Blaise Pascal's name.

    Medium · Also offered: Henri Poincaré, Antoine Lavoisier, Pierre-Simon Laplace · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  4. Which element has the atomic number 6?

    Carbon

    Carbon is element 6 on the periodic table; boron, nitrogen, and oxygen are neighboring light elements.

    Medium · Also offered: Boron, Nitrogen, Oxygen · Source: Royal Society of Chemistry: Carbon

  5. Which gas is chiefly responsible for the fizz in most carbonated drinks?

    Carbon dioxide

    Carbon dioxide dissolves in the drink under pressure and comes back out as bubbles once the bottle is opened and that pressure drops.

    Medium · Also offered: Oxygen, Nitrogen, Hydrogen · Source: Encyclopaedia Britannica, 'Carbonation'

  6. Which astronomer revived the Sun-centered model during the Renaissance?

    Copernicus

    Nicolaus Copernicus revived heliocentric astronomy during the Renaissance.

    Medium · Also offered: Kepler, Galileo, Aristarchus · Source: Encyclopaedia Britannica

  7. What substance do coral polyps secrete to build reef skeletons?

    Calcium carbonate

    The compound is aragonite, a crystal form of calcium carbonate that also makes up limestone and chalk. Individual polyps are only a few millimeters wide, but generations of them building on top of each other's skeletons slowly form an entire reef.

    Medium · Also offered: Silicon dioxide, Calcium phosphate, Chitin · Source: NOAA: Coral reef structure

  8. Corals are most closely related to which other animals?

    Jellyfish and sea anemones

    Coral polyps are cnidarians, the same group as jellyfish and sea anemones, and they carry the same stinging cells on their tentacles. A reef is the limestone left behind by generations of those polyps, built up over thousands of years.

    Medium · Also offered: Sponges and sea squirts, Starfish and sea urchins, Clams and snails · Source: NOAA: What are corals?

  9. Roughly how long did dinosaurs exist before the non-bird lineages died out?

    About 165 million years

    Dinosaurs appeared in the Triassic around 230 million years ago and the non-bird lineages died out 66 million years ago, a reign of roughly 165 million years. Modern humans have managed about 0.3 million so far.

    Medium · Also offered: About 65 million years, About 250 million years, About 400 million years · Source: Natural History Museum: Dinosaurs

  10. In which century did the dodo become extinct?

    The 17th century

    The dodo was a large flightless pigeon relative found only on Mauritius. Dutch sailors reached the island in 1598, and between hunting and the rats, pigs and monkeys that came ashore with them the bird was gone within decades. The last widely accepted sighting was in 1662.

    Medium · Also offered: The 16th century, The 18th century, The 19th century · Source: Natural History Museum: Dodo

  11. Whose 1929 paper established that a galaxy's redshift increases with its distance from us?

    Edwin Hubble

    Hubble's 1929 paper plotted the distances of galaxies against their redshifts and found the two rise together, the first solid evidence that the universe is expanding. Vesto Slipher had measured many of those redshifts years earlier; the distances were the piece Hubble supplied.

    Medium · Also offered: Vesto Slipher, Milton Humason, Georges Lemaitre · Source: NASA Science

  12. Which element formed largely before the first stars?

    Hydrogen

    Hydrogen formed largely in the first few minutes after the Big Bang, before the first stars existed. It remains the most abundant element in the universe, making up roughly 75% of ordinary matter by mass.

    Medium · Also offered: Carbon, Nitrogen, Potassium · Source: NASA Science and NOAA reference material

  13. What process turns a cut apple dark once it is left out in the air?

    Enzymatic browning

    Cutting an apple breaks its cells open and lets an enzyme meet oxygen and the fruit's own phenols, turning them into brown pigments within minutes. Lemon juice slows it because acid and vitamin C get in the way, and so does dropping the slices into cold water, which keeps the oxygen out.

    Medium · Also offered: Caramelisation, The Maillard reaction, Fermentation · Source: American Chemical Society, Why Do Cut Apples Turn Brown?

  14. How does freezing rain form?

    Snow melts in a warm layer aloft, then the raindrops freeze the instant they touch a surface that is below freezing

    Freezing rain needs a temperature sandwich. Snow falls into a layer of above-freezing air and melts, then passes through air too shallow or too mild to refreeze it, so it arrives as liquid and turns to glaze the moment it lands on a road or a power line. If the cold layer near the ground is deeper, the drops refreeze in mid-air instead and fall as sleet.

    Medium · Also offered: Raindrops refreeze into small ice pellets while falling through cold air near the ground; Droplets are carried up and down inside a storm cloud, adding a layer of ice on each trip; Water vapour turns straight to ice on the ground without ever having been liquid · Source: NOAA JetStream: Freezing rain

  15. What geological feature intermittently erupts columns of hot water and steam?

    Geyser

    A geyser is a hot spring with a constriction underground, so pressure builds until the water flashes to steam and throws the column upward. A fumarole vents only steam and gas, and a mud pot bubbles acidic mud.

    Medium · Also offered: Fumarole, Mud pot, Travertine terrace · Source: U.S. National Park Service, 'How Geysers Work'

  16. The SI unit of frequency honours which German scientist?

    Heinrich Hertz

    The hertz, the SI unit of frequency, honours Heinrich Hertz.

    Medium · Also offered: Max Planck, Albert Einstein, Wilhelm Röntgen · Source: BIPM SI Brochure, 9th edition; Encyclopaedia Britannica

  17. Which element is named after the Greek sun god, because it was first detected in sunlight?

    Helium

    Astronomers found an unexplained yellow line in the Sun's spectrum during the 1868 eclipse and named the new element for Helios. It was not found on Earth until 1895.

    Medium · Also offered: Neon, Argon, Radon · Source: Royal Society of Chemistry, Periodic Table

  18. What is the chemical symbol for mercury?

    Hg

    Mercury is represented by Hg, derived from its Greek name hydrargyrum.

    Medium · Also offered: He, Hf, Ho · Source: Royal Society of Chemistry, Periodic Table: Mercury

  19. What is the air doing inside the eye of a mature hurricane?

    Sinking, warming and drying as it descends

    Air descends through the eye, warming and drying as it sinks, which clears the cloud and leaves the calm blue hole that satellite images show. The violently rising air is in the eyewall immediately outside it, where the strongest winds and heaviest rain sit.

    Medium · Also offered: Rising rapidly into towering thunderclouds, Rushing inward across the sea surface, Spinning faster than it does in the eyewall · Source: NOAA JetStream: Hurricane structure

  20. What makes a halo around the sun or moon?

    ice crystals aloft

    Halos form when light is refracted and reflected by ice crystals in high clouds.

    Medium · Also offered: water droplets aloft, dust particles aloft, smoke particles aloft · Source: WMO International Cloud Atlas

  21. Approximately how hot can a lightning channel become?

    About 30,000 kelvins

    A lightning channel can briefly reach about 30,000 kelvins, hotter than the Sun's visible surface. The surrounding air expands explosively when heated, producing thunder.

    Medium · Also offered: About 3,000 kelvins, About 10,000 kelvins, About 100,000 kelvins · Source: NOAA: Lightning science

  22. Which scientist is credited with discovering polonium?

    Marie Curie

    Marie Curie and Pierre Curie announced the discovery of polonium in 1898.

    Medium · Also offered: Henri Becquerel, Ernest Rutherford, Lise Meitner · Source: Nobel Prize Outreach

  23. What biological process does a caterpillar undergo as it becomes an adult butterfly?

    Metamorphosis

    Butterflies go through complete metamorphosis, passing through egg, larva, pupa and adult stages, with the body largely rebuilt inside the pupa.

    Medium · Also offered: Molting, Regeneration, Budding · Source: Encyclopaedia Britannica, 'Metamorphosis (biology)'

  24. What term describes animals that are active mainly at night?

    Nocturnal

    Nocturnal animals are active at night. Diurnal ones are active by day and crepuscular ones around dawn and dusk, while arboreal describes living in trees rather than any time of day.

    Medium · Also offered: Diurnal, Crepuscular, Arboreal · Source: Encyclopaedia Britannica, 'Nocturnal'

  25. What gives an octopus's blood its blue color?

    Copper-based hemocyanin

    Octopus blood is blue because its oxygen-carrying hemocyanin is copper-based.

    Medium · Also offered: Iron-based hemoglobin, Iron-based hemerythrin, Vanadium-based hemovanadin · Source: Smithsonian Ocean: Octopus

  26. What is the common name for a bright patch of light that appears beside the Sun when ice crystals hang in the air?

    Sun dog

    A sun dog is a bright, often faintly rainbow-tinted patch sitting about 22 degrees to the left or right of the Sun, at the same height above the horizon, and they frequently appear in pairs. Flat, plate-shaped ice crystals drifting horizontally in high cloud bend the sunlight sideways to make them. The formal name is a parhelion.

    Medium · Also offered: Green flash, Moonbow, Corona · Source: WMO International Cloud Atlas

  27. What is the chemical symbol for lead?

    Pb

    Lead is represented by Pb, derived from the Latin word plumbum.

    Medium · Also offered: Pd, Pt, Po · Source: Royal Society of Chemistry, Periodic Table: Lead

  28. Which combination of optical processes creates a primary rainbow?

    Refraction, reflection, and dispersion

    Sunlight refracts as it enters a raindrop, reflects from the inside, and disperses into its component colors. The different colors leave the drop at slightly different angles.

    Medium · Also offered: Scattering, diffraction, and absorption; Polarization, interference, and diffraction; Fluorescence, absorption, and scattering · Source: NOAA: Rainbow formation

  29. Why does the daytime sky normally look blue?

    Rayleigh scattering

    Air molecules scatter shorter blue wavelengths more strongly than longer wavelengths.

    Medium · Also offered: Mie scattering, Diffuse reflection, Specular reflection · Source: NASA Science, Why Is the Sky Blue?

  30. What is the chemical symbol for tin?

    Sn

    Tin is represented by Sn, derived from the Latin word stannum.

    Medium · Also offered: Sc, Se, Si · Source: Royal Society of Chemistry, Periodic Table: Tin

  31. What percentage of the solar system's mass is in the Sun?

    About 99.9%

    The Sun's mass gives it overwhelming gravitational control over the solar system. All the planets, moons, asteroids, and comets together make up only a small remainder.

    Medium · Also offered: About 88.6%, About 95.4%, About 98.2% · Source: NASA Science: Sun facts

  32. Metrology is easily mistaken for meteorology. What does metrology actually cover?

    The science of measurement

    Metrology defines units, maintains the standards everything else is measured against, and states how uncertain any measurement is. It is the field behind the SI base units, including the 2019 redefinition of the kilogram in terms of the Planck constant.

    Medium · Also offered: Weather and forecasting, Meteors and meteorites, The extraction and working of metals · Source: International Bureau of Weights and Measures (BIPM)

  33. A steel spoon and a wooden spoon left in the same room are the same temperature, yet the steel one feels colder. Which property of steel explains that?

    Thermal conductivity

    Steel carries heat away from your skin far faster than wood does, so your hand cools quickly at the point of contact and your nerves report cold. Wood is a poor conductor, so the heat stays near your fingers and the spoon feels closer to body temperature.

    Medium · Also offered: Thermal expansion, Thermal emissivity, Specific heat capacity · Source: OpenStax University Physics

  34. What is Venus's approximate average surface temperature?

    About 465 °C

    This makes Venus hotter than Mercury even though Mercury sits closer to the Sun, because Venus's thick carbon dioxide atmosphere traps heat in a runaway greenhouse effect. Surface pressure is also about 92 times Earth's, similar to the crushing pressure nearly a kilometer under the ocean.

    Medium · Also offered: About 288 °C, About 717 °C, About 1,043 °C · Source: NASA Science: Venus facts

  35. What makes a cut onion sting the eyes?

    Volatile sulfur compounds

    Cutting an onion releases volatile sulfur compounds that irritate the eyes.

    Medium · Also offered: Volatile nitrogen compounds, Volatile aldehyde compounds, Volatile phenol compounds · Source: American Chemical Society, The Chemistry of Onions

  36. Name tungsten's chemical symbol.

    W

    Tungsten's chemical symbol is W, derived from its historical name wolfram. The alternatives are also valid one-letter chemical symbols.

    Medium · Also offered: K, S, V · Source: Royal Society of Chemistry, Periodic Table: Tungsten

Hard Science and Nature Trivia Questions

  1. What is a trophic cascade?

    A chain of ecological effects caused by changes at a higher feeding level

    Removing or restoring a top predator ripples down through the levels below it. The return of wolves to Yellowstone is the best-known example.

    Hard · Also offered: A stepwise transfer of energy through a food web, A rise in toxin concentration at successively higher feeding levels, A gradual replacement of one ecological community by another · Source: Encyclopaedia Britannica, 'Trophic cascade'

  2. What are isotopes?

    Atoms of the same element with different numbers of neutrons

    Isotopes share a proton count, so they are the same element and behave the same chemically, but differ in neutrons and therefore in mass. Atoms that have gained or lost electrons are ions instead.

    Hard · Also offered: Atoms with different numbers of protons, Molecules with different arrangements of atoms, Atoms that have gained or lost electrons · Source: Encyclopaedia Britannica, 'Isotope'

  3. Which geological era is commonly known as the Age of Mammals?

    Cenozoic Era

    The Cenozoic began about 66 million years ago, after the extinction that ended the dinosaurs, and mammals diversified into most of the forms alive today.

    Hard · Also offered: Mesozoic Era, Paleozoic Era, Neoproterozoic Era · Source: Encyclopaedia Britannica, 'Cenozoic Era'

  4. Which physicist identified the atomic nucleus through gold-foil scattering?

    Ernest Rutherford

    Ernest Rutherford inferred the atomic nucleus from gold-foil scattering results.

    Hard · Also offered: Niels Bohr, Joseph John Thomson, Max Planck · Source: Encyclopaedia Britannica

  5. Which phenomenon occurs when a massive object bends and magnifies light from a more distant object?

    Gravitational lensing

    A foreground mass curves spacetime and redirects the light passing it, so a background galaxy can appear brightened, distorted, or even repeated as multiple images.

    Hard · Also offered: Doppler shift, Stellar parallax, Atmospheric refraction · Source: NASA Science, 'Gravitational Lensing'

  6. Why can't the Hubble Space Telescope photograph the Apollo spacecraft on the Moon's surface clearly?

    Insufficient angular resolution

    Hubble’s angular resolution is not fine enough to distinguish an Apollo spacecraft, which is only a few meters across, from the lunar surface. Its roughly 0.05-arcsecond resolution corresponds to details about 100 meters wide at the Moon.

    Hard · Also offered: Limited light-gathering power, Inadequate image contrast, Restricted pointing precision · Source: NASA Hubble: Hubble resolution

  7. What are the two major groups of seed plants?

    Gymnosperms and angiosperms

    Seed plants are divided into gymnosperms, whose seeds are exposed, and angiosperms, whose seeds develop inside flowers and are usually enclosed in fruits.

    Hard · Also offered: Conifers and cycads, Ginkgoes and gnetophytes, Monocots and eudicots · Source: U.S. Forest Service: Seed plants

  8. What is the term for a symbiotic relationship in which both organisms benefit?

    Mutualism

    In mutualism each partner gains something. In commensalism one gains and the other is unaffected, and in parasitism one gains at the other's expense.

    Hard · Also offered: Parasitism, Commensalism, Competition · Source: Encyclopaedia Britannica, 'Mutualism'

  9. Who developed the induction motor for alternating-current systems?

    Nikola Tesla

    Nikola Tesla developed the induction motor for alternating-current systems and patented his design in 1888. Its simple, brushless construction helped make AC power practical for widespread use.

    Hard · Also offered: Thomas Edison, Michael Faraday, Elihu Thomson · Source: Encyclopaedia Britannica

  10. What is the name of the point in an orbit where an object is closest to the Sun?

    Perihelion

    Perihelion is the closest point to the Sun and aphelion the farthest. Perigee is the equivalent closest point to Earth, and a barycenter is the shared center of mass two bodies orbit.

    Hard · Also offered: Aphelion, Perigee, Barycenter · Source: NASA Science, 'Perihelion and Aphelion'

  11. Compared with an identical clock at sea level, how does a clock high on a mountain run?

    Slightly faster

    Gravity slows time, so a clock deeper in the Earth's gravity ticks more slowly than one further out. A mountain-top clock therefore gains on a sea-level one, by nanoseconds a day. Atomic clocks have picked up the difference over a height change of about a foot, and GPS satellites have to correct for it to fix your position.

    Hard · Also offered: Slightly slower; At exactly the same rate; Differently, but by far too little to have ever been measured · Source: NIST: Relativity and time

  12. What does the endosymbiotic theory propose about the origins of mitochondria and chloroplasts?

    They descended from free-living bacteria

    The theory holds that free-living bacteria were engulfed by an ancestral cell and became permanent residents. Both organelles still carry their own DNA and divide on their own, which is the strongest evidence for it.

    Hard · Also offered: They arose by infolding of the host cell's plasma membrane, They formed from duplicated pieces of the host cell's nucleus, They developed from protein-rich droplets inside ancestral cells · Source: Encyclopaedia Britannica, 'Endosymbiotic theory'

  13. What system currently rates U.S. tornado intensity?

    Enhanced Fujita Scale

    The scale runs from EF0 to EF5 and estimates wind speed from the damage left behind, such as how buildings and trees are torn apart, rather than from direct measurement. It replaced the original Fujita Scale, devised by scientist Tetsuya Fujita, in 2007.

    Hard · Also offered: Fujita Scale, TORRO Scale, International Fujita Scale · Source: NOAA: Enhanced Fujita scale

  14. Which physicist formulated matrix mechanics, the first complete formulation of quantum theory?

    Werner Heisenberg

    Heisenberg worked it out in 1925 while recovering from hay fever on the island of Helgoland, describing an atom only through quantities that can actually be measured, arranged in arrays. Schrodinger's wave mechanics arrived a year later and the two turned out to be equivalent.

    Hard · Also offered: Erwin Schrodinger, Paul Dirac, Wolfgang Pauli · Source: Nobel Prize

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