95 Fun Facts About Science Trivia for Kids

Which planet is known as the Red Planet?

Mars looks orange-red because minerals in its dusty soil have rusted, just like an old nail left out in the rain.

Which is the largest planet in our Solar System?

Jupiter's powerful magnetic field traps charged particles in belts of radiation so intense that it can damage the spacecraft sent to explore it.

Which planet orbits closest to the Sun?

Mercury is closest to the Sun and circles it in just 88 Earth days, yet one sunrise to the next there takes 176 Earth days.

What kind of object is the Sun?

The Sun is an ordinary star that happens to sit right at the centre of our Solar System. It only looks so big and bright because it is far closer to us than any other star.

Which gas do plants take in from the air to make their food?

Carbon dioxide and water, with sunlight, become sugar in photosynthesis, and the plant gives off oxygen as a leftover.

At what temperature does water freeze?

0 °C is where water turns to ice at one atmosphere, which is 32 degrees Fahrenheit; it boils at 100 °C.

What is the chemical formula for water?

H2O means two hydrogen atoms joined to one oxygen atom, and although hydrogen and oxygen are both gases, together they make liquid water.

What do some of a baby's bones do as it grows?

They fuse together as a child grows, and the gaps between a newborn's skull plates let the head squeeze through at birth.

Who was the first person to walk on the Moon?

Neil Armstrong took over steering the lunar lander to avoid a rocky crater, then became the first person to step onto the Moon.

Which is the largest organ in the human body?

Skin is your largest organ, and its outer layer keeps renewing itself, making new cells to replace the old ones that flake off.

Which force pulls a dropped ball down toward the ground?

Gravity makes a hammer and a feather fall at the same rate when no air slows them, as an Apollo 15 astronaut showed on the Moon.

Which part of a plant takes in water from the soil?

The roots soak up water through tiny root hairs, which give them a much larger surface area so they can take in far more.

What do we call an animal that eats mainly plants?

A herbivore often has wide, flat back teeth for grinding tough leaves and grass, while a carnivore has sharp teeth for tearing meat.

Which natural material is the hardest of all?

Diamond sits at the very top of the Mohs hardness scale, so it can scratch every other natural material but almost nothing can scratch it.

Which rock is so full of tiny gas bubbles that it can float on water?

Pumice is packed with gas bubbles trapped as it erupted from a volcano, so rafts of it can float on the ocean for years before sinking.

Which type of rock forms when hot melted rock cools down and hardens?

Igneous rock that cools slowly underground grows big crystals, like granite, while lava that cools fast at the surface makes fine-grained basalt.

What are the flat layers that sedimentary rocks build up in called?

Strata pile up one on top of another over time, so the deeper a layer lies, the older it usually is.

Heat and pressure deep underground can change limestone into which rock?

Marble is limestone whose crystals regrew under heat and pressure, and Michelangelo carved his statue of David from a block of it.

Which ancient remains get their name from a Latin word meaning 'dug up'?

Fossils take their name from Latin fossilis, 'dug up', and the English word once meant any rock or mineral dug out of the earth, not just ancient remains.

Before a volcano erupts, melted rock collects deep underground in what?

A magma chamber can empty so fast in a huge eruption that the ground above caves in, leaving a giant bowl-shaped hollow called a caldera.

Which instrument records the waves an earthquake sends through the ground?

A seismograph records the ground's shaking, and scientists use those records to work out where an earthquake struck and how strong it was.

Which of these metals is a magnet able to pull on?

Iron, nickel and cobalt are the classic magnetic metals, which is why a magnet sticks to most steel, an alloy of iron, but not to an aluminium can.

Which four states of matter can you see in everyday life?

Solid, liquid, gas and plasma are the four states seen in everyday life, and plasma is gas so energized that electrons break free of its atoms, which is how a neon sign glows.

When water on the surface of a puddle turns into a gas and disappears into the air, what is that called?

Only the fastest-moving molecules escape, so evaporation cools whatever is left behind, which is why sweat cools you down.

Water vapor turning back into liquid drops on the outside of a cold glass is an example of what?

Condensation is also why glasses fog up when someone steps from a cold, air-conditioned room out into warm, humid air.

Clouds are made mostly of what?

Tiny water droplets and ice crystals make up clouds, and the droplets are so small and light that they stay floating in the air instead of falling.

What is the lowest layer of Earth's atmosphere, where most weather happens, called?

The troposphere holds nearly all of the air's water vapour, which is why almost all clouds, rain and storms happen inside it.

Which part of the upper atmosphere soaks up most of the Sun's harmful ultraviolet light?

The ozone layer was thinned by CFC chemicals from sprays and fridges, but after the Montreal Protocol phased them out, it is expected to recover within decades.

Which gas, lighter than air and unable to burn, is used to fill party balloons?

Helium is the second-lightest element and cannot burn, which is why it replaced explosive hydrogen in balloons and airships; the Sun makes helium by fusing hydrogen.

Which instrument measures how hot or cold something is?

A classic glass thermometer works because the liquid inside expands as it warms, so a thin line of it rises up the narrow tube.

Roughly how fast does sound travel through air at room temperature?

About 343 meters per second is roughly a kilometer every three seconds, and a plane flying faster than that makes shock waves heard as a sonic boom.

In a main rainbow, which color is on the outer edge of the arc?

Red is on the outer edge of a main rainbow and violet on the inside, while a fainter second rainbow outside it shows the colors in reverse.

What happens when you bring the north ends of two magnets close to each other?

They push apart because like poles repel, and that same magnetic force is what swings a compass needle into line with Earth's magnetic field.

What is the fixed point that a lever turns on called?

The farther from the fulcrum you push, the less force you need to lift the load, though you have to push it through a longer distance.

Which simple machine is a ramp that helps push a heavy box to a higher place?

An inclined plane is also hiding inside every screw, whose thread is really a narrow ramp wrapped around a rod.

Which simple machine is a wheel with a rope running over it, used to lift things like a flag up a pole?

Pulleys can be joined together into a block and tackle, which lets a person lift a load far heavier than they could pull up with a single rope.

Rubbing two sticks together can start a fire because of which force?

Friction is also what lights a match: striking its tip against a rough strip makes enough heat to set it burning.

What are the heart's two lower sections called?

The ventricles pump blood out of the heart: the right one sends it to the lungs, and the left one sends it all around the body.

Which large muscle under your lungs does most of the work when you breathe?

When it tightens and flattens, your lungs get bigger and air rushes in; hiccups are the diaphragm twitching.

Which animal group has three body parts, six legs and a pair of antennae?

Insects wear their skeleton on the outside, so to grow bigger they must molt, shedding the old one and forming a new, larger one.

What are baby frogs called while they swim in water breathing with gills?

Tadpoles have tails and gills for life underwater, then grow legs and lungs as they become frogs that can breathe air.

Which feature do all mammals share?

They feed their young with milk, and a mother's first milk is packed with antibodies that help protect her newborn from infections.

Which group of animals has dry, scaly skin, breathes air and lays eggs on land?

Reptiles can't keep their bodies warm on their own, which is why snakes and lizards move into the sun to warm up and get active.

A caterpillar changing into a butterfly is an example of what process?

Metamorphosis lets the young and the adult live very different lives: a caterpillar chews leaves, while a butterfly sips nectar from flowers.

In a food chain, what do we call a living thing like grass or algae that makes its own food?

A producer like grass makes its own food from sunlight, so the energy in a rabbit, and in the fox that eats it, first came from the grass.

Fungi and bacteria that break down dead organisms and recycle nutrients are called what?

Decomposers such as fungi pour digestive juices onto dead matter and then soak up the nutrients that dissolve, instead of swallowing their food.

What do we call bees carrying tiny grains from one flower to another?

Pollination is why many flowers have bright colours, sweet scents and nectar: they draw in the animals that carry pollen between them.

Which of these animals hibernates through the winter?

Hedgehogs hibernate to save energy while food is scarce, yet most wake up at least once during the winter to move to a new nest.

What is the trick called when a leopard's spotted coat helps it hide?

Camouflage works in the sea too: a shark's dark back blends with the deep water below, while its pale belly matches the bright surface.

Animals with a backbone, like fish, birds and mammals, are called what?

Vertebrates are far outnumbered: over 95 percent of described animal species, from snails to jellyfish, have no backbone at all.

Which SI unit is used to measure force?

The newton is named after Isaac Newton, whose third law explains rockets: they throw hot gas out backward, and the gas drives the rocket forward.

Which SI unit is used to measure energy?

The joule is named after James Prescott Joule, who showed that heat and motion are both forms of energy that can be changed into each other.

Density is found by dividing an object's mass by what?

Density is mass divided by volume, so a material with more mass packed into the same volume is denser. Ice is less dense than liquid water, which is why ice cubes float.

A material like rubber or glass that does not let electricity flow through it easily is called what?

An insulator such as rubber or glass holds its electrons tightly to their atoms, so current cannot flow easily; the plastic around a wire is there to keep the current inside the copper.

Which instrument would you use to look at something far too small to see with your eyes?

A microscope's lenses bend light to magnify, but light can't show the tiniest details, so electron microscopes use beams of electrons instead.

How long does the Moon take to go once around the Earth and return to the same phase?

The Moon takes about 29.5 days to return to the same phase, which is why a full moon comes roughly once a month, a word related to 'moon'.

What do we call wind or water carrying broken rock pieces away?

The Grand Canyon is erosion on a giant scale: the Colorado River has been carrying rock away for millions of years.

Which blood cells fight germs and infection in your body?

White blood cells are the body's germ fighters, and some of them make antibodies, special proteins that help the body spot invaders and get rid of them.

Which planet has the hottest surface in the Solar System?

Venus has an atmosphere so thick that it traps heat like a greenhouse, making its surface hot enough to melt lead.

Which pigment gives plant leaves their green colour?

Chlorophyll gets its name from Greek words for 'pale green' and 'leaf', and it captures energy from light so the plant can make its own food.

Which planet has the largest and most easily seen rings?

Saturn's rings are billions of chunks of ice and rock, thought to be pieces of comets or moons that broke up before they reached the planet.

Which animal is the largest known to have ever lived?

The blue whale can weigh well over 100 tonnes, yet it grows that big on a diet made almost entirely of krill, tiny shrimp-like animals.

Which animal is the fastest runner on land?

The cheetah is the fastest land animal, but it can only keep up its top speed for a short sprint, so it creeps close to its prey before charging.

Which is the tallest animal living on land today?

A giraffe's neck has the same number of bones as a human neck, seven, but each one is greatly stretched.

Which sea animal has three hearts?

The octopus has one main heart for its body and two smaller hearts that pump blood through its gills, and its blood is blue because it carries oxygen with copper.

Which group of animals do spiders, scorpions and ticks belong to?

Spiders, like most arachnids, can't chew, so they flood their prey with digestive juices and then suck up the liquid.

Which is the heaviest and largest living bird?

The ostrich is far too heavy to fly, but it is built to run, and it is the fastest two-legged animal on Earth.

Which species is the smallest bird in the world?

The bee hummingbird is found in Cuba, and on cold nights it can let its body cool into a sleep-like torpor to save energy.

Which Australian mammal has a duck-like bill and lays eggs?

When the first platypus specimens reached Europe, many scientists believed the platypus was a fake stitched together from different animals.

Which animals are the only mammals that can truly fly?

Bats fly on wings of thin skin stretched between long fingers, so they can twist fast enough to catch mosquitoes in midair, while flying squirrels can only glide.

Which teeth often arrive last, in the late teens?

Wisdom teeth develop later than the other teeth, and they can get stuck and need removing when there isn't enough space for them to come through.

Which is the hardest substance in the human body?

Tooth enamel is the hardest substance in the body, yet acids made by mouth bacteria from sugary food can still wear holes in it, which is how cavities start.

Which is the smallest bone in the human body?

The stapes, in the ear, is one of three tiny bones that pass sound vibrations from the eardrum toward the inner ear, and its name means stirrup.

Which planet is the farthest known planet from the Sun?

Neptune was found in 1846 after mathematicians predicted where it should be. It takes about 165 Earth years to orbit the Sun once.

Which of these would stop sound from traveling?

A vacuum has no matter for sound's vibrations to travel through, so sound can't cross space, even though sunlight races through that same vacuum to reach Earth.

What is the chemical symbol for gold?

Au comes from aurum, the Latin word for gold, and because gold doesn't corrode, it is used to coat electrical connectors.

Which of Earth's oceans is the largest and deepest?

The Pacific Plate meets many surrounding plates of Earth's crust, so the Pacific's rim, the Ring of Fire, has more earthquakes and volcanoes than anywhere else.

Which mountain is the highest above sea level?

Mount Everest stands about 8,849 m tall, and the air near its summit is so thin that low oxygen is one of the biggest dangers climbers face.

Thunder is the sound made by what?

A lightning bolt heats the air around it so fast that the air expands explosively, making a boom. You see the flash first because light travels far faster than sound.

Which glass object can split white light into a rainbow of colours?

A prism bends each colour of light by a different amount, which fans white light out into a spectrum and shows it is really a mix of colours.

Where is most of Earth's fresh water?

Over two-thirds of Earth's fresh water is locked up in glaciers and ice sheets, and most of the rest lies underground, leaving rivers and lakes only a tiny share.

Which of these animals is found in the wild only in the Arctic?

Polar bears live on and around the frozen Arctic Ocean, where they often wait beside seals' breathing holes to catch their main prey.

Which medicine did Alexander Fleming discover in 1928?

Penicillin came from a mould that had grown by accident on one of Fleming's dishes of bacteria and left a bacteria-free circle around itself.

Which chemist's periodic table left gaps for undiscovered elements?

Dmitri Mendeleev predicted what some of those missing elements would be like, and when gallium, scandium and germanium were found, his predictions proved remarkably accurate.

A camel's hump is often thought to hold water, but what does it really store?

Fat is what a camel's hump stores, and when food runs short, the camel's body uses that fat up for energy.

Where do flamingos get their pink colour from?

Their food gives flamingos their colour: chicks hatch greyish and turn pink from carotenoid pigments in the algae and tiny shrimp they eat.

In which fish does the male carry the eggs in a pouch until they hatch?

The seahorse mother places her eggs in the father's pouch, and he carries them until the babies are born, so it is the dad that gives birth.

The leaves of which tree make up most of a koala's diet?

Eucalyptus leaves are tough and low in energy, so koalas save energy by sleeping as much as 20 hours a day.

A shark's skeleton is made of which flexible material instead of bone?

Cartilage, the same bendy stuff in your nose, is much lighter than bone, which helps a shark stay afloat without a swim bladder.

Which sea animal has no brain at all?

The sponge is so simple that it has no true tissues, let alone a brain, and it feeds by keeping seawater flowing through its body to filter out food.

Which mosquitoes bite people to drink blood?

Only the females bite, because they need the protein in blood to make their eggs, while both males and females feed on flower nectar.

A person on the Moon weighs about what fraction of their weight on Earth?

About one-sixth is how strongly the Moon pulls compared with Earth, which is why moonwalking astronauts could bounce along in heavy spacesuits.

What does a barometer measure?

Air pressure readings help forecasters, because a rapid drop in pressure usually means cloudy, rainy or windy weather is on its way.

What shape is a molecule of DNA, the instruction code inside living cells?

A double helix can split down the middle into two strands, and each one serves as a pattern for building a new partner, which is how cells copy their DNA.

Which sea animal can regrow its whole body from one arm?

A few kinds of starfish can grow a whole new body from one arm, and despite the name, the starfish is not a fish at all but a relative of sea urchins.