Science and Nature
0Loading crowd target
0Loading crowd target
9correct to beat the crowd
99 free Science and Nature trivia questions with answers — science & nature quiz, new questions added Oct 2026.
60 free science and nature trivia questions with answers. Think you know your elements from your enzymes? From the speed of light to the deepest ocean trench, this 99-question science and nature quiz covers the full spectrum — physics, chemistry, biology, astronomy, earth science, ecology, and the scientists who shaped our understanding of the world. Easy enough to start, hard enough to humble.
30 of 99 questions with answers and explanations. Play the quiz
Q 01Iron oxide, better known as rust, gives which planet its famous colour?
Mars
Mars. Its rusty dust is so fine that winds can whip it into storms covering the whole planet; one in 2018 blotted out the Sun and ended the solar-powered Opportunity rover's mission.
Q 02What gas do plants absorb from the atmosphere during photosynthesis?
Carbon dioxide
Carbon dioxide. Light energy drives the plant to build sugars from carbon dioxide and water, and the oxygen is given off as a by-product.
Q 03Which household antiseptic fizzes on a cut as an enzyme in blood breaks it down?
Hydrogen peroxide
Hydrogen peroxide, H2O2, is water's formula plus one oxygen atom; the enzyme catalase, found in blood and most living cells, splits it back into water and oxygen gas, and those bubbles are the fizz.
Q 04How many bones are in the adult human body?
206
206 is the usual adult count. A newborn has around 270 bones, and the number falls because many of them fuse together as the skeleton grows.
Q 05Which is the only mammal capable of true, powered flight?
Bat
Bat. Its wing is a modified hand, a thin membrane stretched between very long finger bones that it can flap; flying squirrels, sugar gliders and colugos can only glide.
Q 06What is the largest planet in our solar system?
Jupiter
Jupiter. More than twice as massive as all the other planets combined, it tore comet Shoemaker-Levy 9 apart in 1992 and swallowed the fragments in a string of impacts in July 1994.
Q 07What is the powerhouse of the cell?
Mitochondria
Mitochondria. They descend from free-living bacteria that took up residence inside an ancestral cell, which is why they still carry their own small ring of DNA, passed down from the mother.
Q 08What type of animal is a dolphin?
Mammal
Mammal. Dolphins descend from hoofed land animals that took to the water about 50 million years ago, which is why they still have to surface and breathe air through a blowhole.
Q 09At which of these places does water boil at only about 70°C instead of 100°C?
Mount Everest's summit
Mount Everest's summit. The air pressure there is only about a third of that at sea level, and the less the air presses down on water, the lower the temperature at which it boils.
Q 10Which scientist developed the theory of general relativity?
Albert Einstein
Albert Einstein. In 1919 astronomers photographing a solar eclipse found starlight bending around the Sun just as his theory predicted, and the headlines made him an international celebrity.
Q 11What is the hardest natural substance on Earth?
Diamond
Diamond. It is pure carbon, the same element as the soft graphite in a pencil; the difference is that its atoms lock into a rigid three-dimensional lattice while graphite's lie in loose layers.
Q 12What does DNA stand for?
Deoxyribonucleic acid
Deoxyribonucleic acid. Friedrich Miescher first isolated it in 1869 from the pus on used hospital bandages, and called it nuclein because it came from the nuclei of cells.
Q 13Which element has the atomic number 1?
Hydrogen
Hydrogen. Its name comes from the French hydrogène, 'water-former', because burning the gas produces water.
Q 21Which ocean trench holds the deepest known point on Earth?
Mariana Trench
The Mariana Trench. Its Challenger Deep lies nearly 11 km down, and people first reached the bottom in January 1960, when Jacques Piccard and Don Walsh descended in the bathyscaphe Trieste.
Q 22What type of rock is formed from cooled lava or magma?
Igneous
Igneous. The speed of cooling sets the texture: magma trapped underground cools slowly and grows large crystals, while lava chilled quickly at the surface turns fine-grained or even glassy.
Q 23What phenomenon causes the Northern Lights (Aurora Borealis)?
Charged solar particles hitting gas
Q 14The giant sequoia is the most massive tree, but which species grows tallest?
Coast redwood
Coast redwood. The record holder, a tree named Hyperion, grows in California's Redwood National Park, which has closed the area around it because off-trail visitors were trampling the forest floor.
Q 15What layer of Earth's atmosphere do we live in?
Troposphere
Troposphere. The lowest layer holds most of the atmosphere's mass and about 99% of its water vapour, which is why almost all weather happens inside it.
Q 16What is the speed of light in a vacuum, approximately?
300,000 km/s
Light travels 299,792,458 metres per second, about 300,000 km/s; the figure is exact by definition because the metre is defined as the distance light covers in 1/299,792,458 of a second.
Q 17Which organ in the human body produces insulin?
The pancreas
The pancreas. Insulin is made there in clusters of cells called the islets of Langerhans, and it takes its name from insula, the Latin for island.
Q 18Which gas makes up nearly four-fifths of the air?
Nitrogen
Nitrogen. Its atoms pair up with a triple bond so strong that plants cannot use the gas directly; lightning and soil bacteria must first 'fix' it into compounds that roots can absorb.
Q 19Which scientist is known as the father of evolution?
Charles Darwin
Charles Darwin. He had worked on the theory for some twenty years without publishing, until an 1858 essay from Alfred Russel Wallace outlining the same idea spurred him into print.
Q 20Which scale was introduced in 1935 to rate the magnitude of earthquakes?
Richter scale
Richter scale. Charles Richter devised it in 1935, but it measures the very largest quakes poorly, so seismologists now report moment magnitude instead.
Charged solar particles hitting gas. The particles follow Earth's magnetic field down toward the polar regions, which is why the glow forms rings around the Arctic and Antarctic.
Q 24An extra chromosome 21 causes which genetic condition?
Down syndrome
Down syndrome. Most people have 46 chromosomes; the extra one usually arises by chance, when a chromosome pair fails to separate as an egg or sperm cell forms, so most cases are not inherited.
Q 25What is the chemical symbol for gold?
Au
Gold's symbol Au comes from the Latin aurum; silver's Ag likewise comes from the Latin argentum.
Q 26In March 2025, astronomers announced 128 new moons for which planet?
Saturn
Saturn. The newcomers are irregular moons only a few kilometres across, probably the fragments of captured moons smashed apart in collisions, and they left every other planet far behind.
Q 27What is the process by which a caterpillar transforms into a butterfly called?
Metamorphosis
Metamorphosis. Inside the chrysalis the caterpillar digests most of its own body, and clusters of cells called imaginal discs, carried since it was in the egg, use the soup to build the butterfly.
Q 28What is Newton's First Law of Motion also known as?
Law of inertia
Law of inertia. Galileo deduced it from balls rolling down inclined planes, overturning the old Aristotelian view that an object comes to rest unless something keeps pushing it.
Q 29Which blood type is known as the universal donor?
O negative
O negative. Its red cells carry none of the A, B or Rh markers that another person's immune system might attack, so hospitals reach for it in emergencies when a patient's blood type is unknown.
Q 30What particle in an atom has a negative charge?
Electron
Electron. J. J. Thomson found it in 1897 while studying cathode rays; it was the first particle smaller than an atom ever discovered, proof that atoms are built from smaller parts.