Science
Science is humanity’s method for understanding the universe, from the tiniest particles to the largest galaxies. Spanning physics, chemistry, biology, astronomy and earth science, it is a favourite trivia category precisely because it blends the things everyone half-remembers from school with facts so strange they sound made up.
The branches of science
Science trivia draws from a handful of great disciplines. Knowing the shape of each helps you place any question fast.
Physics
Forces, energy, the universe’s rules
Gravity, light, motion
Chemistry
Elements and reactions
The periodic table lives here
Biology
Life, cells and evolution
From DNA to ecosystems
Astronomy
Planets, stars and space
The most awe-inspiring category
Earth Science
Rocks, weather and oceans
Volcanoes, climate and tectonics
The Human Body
Anatomy and how we work
Bones, organs and the brain
Science questions that trip people up
These feel like they should be easy, and that’s exactly why they’re quiz gold.
What’s the most abundant gas in Earth’s atmosphere?
Answer: nitrogen (not oxygen)How many hearts does an octopus have?
Answer: threeWhat’s the hardest natural substance?
Answer: diamondWhich planet is the hottest?
Answer: Venus (not Mercury)What’s the powerhouse of the cell?
Answer: the mitochondriaHow long does light from the Sun take to reach us?
Answer: about 8 minutes
Why science makes the best trivia
Science trivia works on two levels. There’s the school-knowledge layer (symbols, forces, cells, planets) that almost everyone half-remembers, and then the surprise layer, where the true facts are so counter-intuitive they beat any fiction. Venus is hotter than Mercury; nitrogen, not oxygen, dominates the air we breathe.
That combination of the familiar and the astonishing is why a good science round is so satisfying: you feel clever when you get one right, and you never forget the ones that surprised you.
Is Pluto a planet? The classification debate
Pluto was considered the ninth planet from its 1930 discovery until 2006, when the International Astronomical Union formally defined "planet" in a way Pluto doesn't meet: it hasn't "cleared its orbital neighbourhood" of other objects. It was reclassified as a "dwarf planet," a decision that remains genuinely contested among astronomers to this day.
| Requirement to be a "planet" (IAU, 2006) | Does Pluto meet it? |
|---|---|
| Orbits the Sun | Yes |
| Is round due to its own gravity | Yes |
| Has "cleared its orbital neighbourhood" | No, this is what disqualifies it |
Science by the numbers
- 118ElementsOn the periodic table
- 8 minSunlightTime to reach Earth
- 206BonesIn the adult body
- ~37TCellsIn the human body
Things nobody knew
The details that separate a fan from a fanatic.
Venus is hotter than Mercury
Even though Mercury is closer to the Sun, Venus’s thick CO₂ atmosphere traps heat, making it the hottest planet at around 465°C.
Air is mostly nitrogen, not oxygen
Earth’s atmosphere is about 78% nitrogen and only 21% oxygen, so the gas we depend on is the minority.
Bananas are slightly radioactive
They contain potassium-40, a natural radioactive isotope that is harmless, but real enough to be a unit scientists joke about.
Hot water can freeze faster than cold
The Mpemba effect: under certain conditions, hotter water freezes quicker than cold, and scientists still debate exactly why.
Your brain runs on about 20 watts
The human brain uses roughly the power of a dim light bulb, yet outperforms supercomputers at many everyday tasks.
There are more stars than grains of sand
Estimates suggest the observable universe holds more stars than all the grains of sand on every beach on Earth.
Fan theories
Some confirmed, some still argued about twenty years on.
- Debated
Pluto should still be classified as a planet
The 2006 IAU reclassification remains actively disputed: some scientists (including figures at NASA) have publicly argued the "orbit-clearing" criterion is flawed, keeping "is Pluto a planet" a live scientific debate, not a settled fact.
- Confirmed
The Mpemba effect is real but not fully explained
Under certain conditions, hot water genuinely can freeze faster than cold water, a repeatedly observed phenomenon, but scientists still don't agree on a single complete explanation for why it happens.
Are you a real fan?
Most people stop at the films. The quiz doesn’t.
- Remembers school scienceElements, planets and basic biology are solid ground for you.
- Follows science newsNew discoveries and space missions are things you actually keep up with.
- Deep-dive enthusiastYou know the debates scientists themselves haven't settled yet.
Prep for a Quelo quiz
Where Science battles are actually won.
- 01The periodic tableElement symbols and basics are among the most common science questions.
- 02Space & the solar systemPlanets, distances and firsts in space come up constantly.
- 03The human bodyBones, organs and cell parts (mitochondria!) are staples.
- 04Famous scientists & lawsNewton, Einstein, Darwin and their big ideas win deeper rounds.
Are you really a Science expert?
7 questions · 10 seconds each · one shot at the leaderboard.
So… how well do you actually know Science?
You just read the guide. Time to prove it, and find out where you’d land on the Quelo leaderboard.