Science Trivia Questions and Answers

From the periodic table to the solar system, these science trivia questions cover chemistry, biology, physics and Earth science. Some are classroom staples, others are tougher. Each answer has a short explanation, so even a wrong guess teaches you something. Great for general knowledge practice or a quick science quiz round.

13 questions · Every answer explained · Fact-checked October 2026

1. 1. Which planet is known as the Red Planet?

   • A. Venus
   • B. Mars
   • C. Jupiter
   • D. Saturn
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   B. Mars — Mars appears reddish because iron oxide (rust) covers much of its surface.

2. 2. What is the chemical symbol for gold?

   • A. Gd
   • B. Go
   • C. Au
   • D. Ag
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   C. Au — Gold's symbol, Au, comes from its Latin name, aurum.

3. 3. Which gas do plants primarily absorb from the air to carry out photosynthesis?

   • A. Oxygen
   • B. Nitrogen
   • C. Carbon dioxide
   • D. Hydrogen
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   C. Carbon dioxide — Plants take in carbon dioxide and, using sunlight, convert it into glucose and oxygen.

4. 4. What is the largest mammal in the world?

   • A. African elephant
   • B. Blue whale
   • C. Giraffe
   • D. Sperm whale
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   B. Blue whale — The blue whale is the largest animal known to have ever existed, larger even than the biggest dinosaurs.

5. 5. What is the freezing point of water in degrees Celsius?

   • A. -10°C
   • B. 0°C
   • C. 10°C
   • D. 32°C
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   B. 0°C — Water freezes at 0°C (32°F) under standard atmospheric pressure.

6. 6. Which mineral scores a perfect 10 on the Mohs hardness scale?

   • A. Quartz
   • B. Topaz
   • C. Corundum
   • D. Diamond
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   D. Diamond — Diamond is the hardest naturally occurring mineral, ranking 10 on the Mohs scale.

   Did you know? Corundum, the mineral that forms rubies and sapphires, sits just below diamond at 9.

7. 7. Which element has the atomic number 1?

   • A. Helium
   • B. Hydrogen
   • C. Oxygen
   • D. Lithium
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   B. Hydrogen — Hydrogen has a single proton, giving it atomic number 1.

   Did you know? Hydrogen makes up roughly three-quarters of all ordinary matter in the universe by mass.

8. 8. Roughly how fast does light travel in a vacuum?

   • A. 30,000 km/s
   • B. 150,000 km/s
   • C. 300,000 km/s
   • D. 3,000,000 km/s
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   C. 300,000 km/s — Light travels at about 299,792 km per second in a vacuum.

   Did you know? Sunlight takes about 8 minutes and 20 seconds to reach Earth.

9. 9. Which blood type is known as the universal red-cell donor?

   • A. AB positive
   • B. O negative
   • C. A negative
   • D. B positive
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   B. O negative — O negative red cells lack A, B and RhD antigens, so they can be given to almost any patient.

   Did you know? AB positive is the opposite: the universal recipient.

10. 10. Which planet has the shortest day in our solar system?

    • A. Mercury
    • B. Saturn
    • C. Jupiter
    • D. Neptune
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    C. Jupiter — Jupiter completes a rotation in just under 10 hours, the fastest of any planet.

    Did you know? That rapid spin makes Jupiter visibly wider at its equator than pole to pole.

11. 11. Which metal has the highest melting point?

    • A. Titanium
    • B. Platinum
    • C. Iron
    • D. Tungsten
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    D. Tungsten — Tungsten melts at about 3,422 °C, the highest of any metal.

    Did you know? That heat resistance is why tungsten was used for incandescent light-bulb filaments.

12. 12. What is the smallest bone in the human body?

    • A. Stapes
    • B. Hyoid
    • C. Malleus
    • D. Coccyx
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    A. Stapes — The stapes, in the middle ear, is about 3 mm long and helps transmit sound to the inner ear.

    Did you know? Its name is Latin for 'stirrup', which it closely resembles.

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

    • A. Oxygen
    • B. Nitrogen
    • C. Argon
    • D. Carbon dioxide
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    B. Nitrogen — Nitrogen makes up about 78% of the atmosphere; oxygen is about 21%.

    Did you know? Argon, at under 1%, is still more abundant than carbon dioxide.