Science trivia questions

Atoms, organs, planets and the speed of sound. Ten random questions per round, each with the why behind the answer.

10 random questions from a bank of 20 · instant feedback · new mix every time.

Science questions are satisfying because the answers are not arbitrary: there is a reason water boils at 100 °C at sea level (the Celsius scale was defined around it) and a reason Venus is hotter than Mercury (a runaway greenhouse atmosphere).

We keep the facts to things you can check in any textbook or on NASA's and NIST's sites, and note where records change, such as moon counts.

Stumped on why a half-lit Moon is called a “first quarter”? ahaboo walks through the Moon's phases with narration and a model you can nudge yourself.

More rounds: General Knowledge trivia · History trivia · Movies trivia · Hard trivia · mixed round

All 20 science questions and answers

  1. What is the chemical symbol for gold?

    Au. From the Latin aurum.

  2. What is the most abundant gas in Earth's atmosphere?

    Nitrogen. Nitrogen makes up about 78% of dry air.

  3. What is the powerhouse of the cell?

    Mitochondria. Mitochondria produce most of the cell's ATP.

  4. How many bones are in the adult human body?

    206. Babies are born with around 300, many of which fuse.

  5. What planet has the most confirmed moons?

    Saturn. Saturn passed 140 confirmed moons in 2023, ahead of Jupiter.

  6. At sea level, water boils at what temperature in Celsius?

    100 °C. 212 is the Fahrenheit figure.

  7. What is H2O more commonly called?

    Water. Two hydrogen atoms, one oxygen.

  8. Which blood type is known as the universal donor for red cells?

    O negative. O negative red cells lack A, B and RhD antigens.

  9. What force keeps the planets in orbit around the Sun?

    Gravity. Newton described it; Einstein refined it as curved spacetime.

  10. Roughly how long does light from the Sun take to reach Earth?

    About 8 minutes. About 8 minutes 20 seconds on average.

  11. What is the largest organ of the human body?

    Skin. The liver is the largest internal organ.

  12. Which element has the atomic number 1?

    Hydrogen. Hydrogen is also the most abundant element in the universe.

  13. What is the speed of sound in air at about 20 °C?

    About 343 m/s. 300,000 km/s is roughly the speed of light.

  14. What type of animal is a Komodo dragon?

    Lizard. It is the largest living lizard.

  15. Which planet is closest to the Sun?

    Mercury. Venus is hotter, though, thanks to its thick atmosphere.

  16. What part of the plant conducts photosynthesis mainly?

    Leaves. Chloroplasts in leaf cells hold the chlorophyll.

  17. What is the pH of pure water at 25 °C?

    7. A pH of 7 is neutral.

  18. DNA has a shape famously described as a…

    Double helix. Described by Watson and Crick in 1953, using Rosalind Franklin's X-ray data.

  19. What is the only mammal capable of true powered flight?

    Bat. Flying squirrels and colugos glide rather than fly.

  20. Which vitamin does skin make when exposed to sunlight?

    Vitamin D. UVB light triggers vitamin D synthesis in the skin.

Questions people ask

What are some easy science trivia questions?

The chemical symbol for gold (Au), the most abundant gas in the air (nitrogen) and the closest planet to the Sun (Mercury) are classic warm-ups.

Which planet has the most moons?

Saturn, after dozens of new small moons were confirmed in 2023. The count changes as telescopes find more, so check the latest NASA figures.

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