You do not need to be a scientist to enjoy this quiz. But you might be surprised how much (or how little) you remember from school.
Chemistry, biology, astronomy, physics... This quiz covers the kind of science knowledge that sticks around long after school. How much of yours is still there?
Pick your level
You do not need to be a scientist to enjoy this quiz. The normal mode sticks to the kind of thing everyone met at school: the formula for water, the planets, chromosomes, the speed of light, what the air is made of. The tricky part is that what seems obvious often turns out to be slightly off.
Hard mode asks about the discoveries and the people behind them, plus a few numbers most of us have never pinned down. No equations, no calculators. Five out of ten there shows a genuinely good science background.
Popular science history tends to credit one famous name per discovery. The real story is usually more crowded, with co-discoverers who were sidelined, colleagues whose data made the breakthrough possible and astronomers who got there slightly earlier. Hard mode gives a few of those people their due.
All ten easy level questions, with the answer and the reasoning behind it.
Correct answer: Carbon dioxide
Carbon dioxide, and they release oxygen in exchange.
Correct answer: 0 °C
0 °C. The 32 you may have spotted is the same point in Fahrenheit.
Correct answer: Gravity
Gravity, the same force that keeps the Moon in orbit.
Correct answer: The brain
The brain, which weighs about 1.4 kilos and uses a fifth of the body's energy.
Correct answer: An atom
An atom, made of protons, neutrons and electrons.
Correct answer: Saturn
Saturn. The other giant planets have rings too, but much fainter ones.
Correct answer: A microscope
A microscope, which opened up the world of cells and bacteria.
Correct answer: Evolution
Evolution by natural selection, set out in On the Origin of Species, 1859.
Correct answer: A star
A star, and a rather ordinary one among billions.
Correct answer: Light travels faster than sound
Light travels far faster than sound. Count the seconds in between to estimate the distance.
Want to warm up before playing or double-check something? Open any question to reveal the correct answer and a short explanation.
Correct answer: H2O
Water is made up of two hydrogen atoms (H2) and one oxygen atom (O), giving the formula H2O. It is one of the most abundant molecules on Earth.
Correct answer: 8
Since 2006, our solar system officially has 8 planets. Pluto was reclassified as a dwarf planet by the International Astronomical Union because it does not gravitationally dominate its orbit.
Correct answer: The skin
The skin is the largest organ of the human body. In an adult, it covers approximately 1.5 to 2 m² and serves functions including protection, temperature regulation and sensory perception.
Correct answer: Albert Einstein
Albert Einstein published the special theory of relativity in 1905 and the general theory in 1915. These works revolutionised physics and our understanding of space, time and gravity.
Correct answer: Mars
Mars is nicknamed the red planet because of its rust-coloured surface, caused by iron oxide. It is one of the most studied planets, with several rovers deployed on its surface.
Correct answer: 46
A human cell contains 46 chromosomes, arranged in 23 pairs. Sex cells (sperm and eggs) contain only 23, which pair up at fertilisation.
Correct answer: Gold
Au is the symbol for gold, from the Latin word 'Aurum'. Gold is a precious metal known since antiquity, used in jewellery, electronics and as a financial safe haven.
Correct answer: Alexander Fleming
Alexander Fleming discovered penicillin by accident in 1928. He noticed that a mould (Penicillium (P. rubens, anciennement nommée P. notatum)) was destroying bacteria in his Petri dish. This discovery transformed modern medicine.
Correct answer: 300,000 km/s
Light travels at approximately 299,792 km/s in a vacuum, roughly 300,000 km/s. According to Einstein's theory of relativity, this is the maximum speed achievable in the universe.
Correct answer: Nitrogen
Nitrogen (N2) makes up about 78 % of Earth's atmosphere. Oxygen (O2) comes second at 21 %. CO2, despite being a major greenhouse gas, makes up only around 0.04%.
Stuck on one, or just curious how nasty it gets? Every hard mode question is here with its answer and the reasoning behind it.
Correct answer: Tungsten
Tungsten, from its other name, wolfram. It has the highest melting point of any metal, around 3,400 °C, which is why it was used for light bulb filaments. Tin is Sn, from the Latin stannum.
Correct answer: O negative
O negative, the universal red cell donor, because its red cells carry no A, B or RhD antigens. AB positive is the opposite case: the universal recipient. Hospitals keep O negative on hand for emergencies when there is no time to test.
Correct answer: −273.15 °C
−273.15 °C, or 0 kelvin, the temperature at which particles have the least possible energy. The figure −459.67 is the same point in Fahrenheit. It can be approached in laboratories but never quite reached.
Correct answer: Alfred Russel Wallace
Alfred Russel Wallace, who reached the same idea while collecting specimens in the Malay Archipelago and sent it to Darwin. Their papers were presented together in London in 1858, a year before On the Origin of Species.
Correct answer: Deoxyribonucleic acid
Deoxyribonucleic acid. The molecule was first isolated by Friedrich Miescher in 1869, long before anyone understood that it carried hereditary information.
Correct answer: Rosalind Franklin
Rosalind Franklin's, taken in her lab at King's College London by her student Raymond Gosling. Watson and Crick saw it without her knowledge before publishing the double helix in 1953. Franklin died in 1958, four years before their Nobel Prize.
Correct answer: 343 metres per second
About 343 metres per second, which works out at roughly 1,235 km/h. That is why you can estimate how far away a storm is by counting the seconds between lightning and thunder: three seconds is about a kilometre.
Correct answer: Hydrogen
Hydrogen, which makes up around three quarters of all ordinary matter by mass. Helium comes second, and most of both were produced in the first minutes after the Big Bang. Nearly everything heavier was forged later inside stars.
Correct answer: That the universe is expanding
That distant galaxies are moving away from us, faster the further away they are, which means the universe is expanding. The Belgian priest and physicist Georges Lemaître had published the same idea two years earlier. Pluto was found in 1930, and light bending was confirmed in 1919.
Correct answer: Na
Na, from the Latin natrium. S on its own is sulphur. Sodium reacts so violently with water that it has to be stored under oil, yet combined with chlorine it becomes ordinary table salt.