Smart Cookie Trivia

40 Science Trivia Questions and Answers (Easy to Hard)

Atoms, planets, cells, and the forces that hold it all together. These start easy and get harder as you go. Tap any question to reveal the answer and a quick fact.

1. 1What is the chemical symbol for gold?Answer

   AuIt comes from aurum, the Latin word for gold.

2. 2Which planet is known as the Red Planet?Answer

   MarsIron oxide, essentially rust, in its dust gives it the color.

3. 3Which gas do plants take in from the air for photosynthesis?Answer

   Carbon dioxideThey use it with sunlight and water to make sugar, releasing oxygen.

4. 4What is the hardest natural substance?Answer

   DiamondIt is pure carbon, with each atom locked to four neighbors.

5. 5How many bones are in the adult human body?Answer

   206Babies are born with around 300; many fuse together as they grow.

6. 6What is the closest star to Earth?Answer

   The SunThe next closest, Proxima Centauri, is about 4.2 light-years away.

7. 7Which substance has the chemical formula H₂O?Answer

   WaterEach molecule is two hydrogen atoms bonded to one oxygen atom.

8. 8What is the largest planet in our solar system?Answer

   JupiterIt has more than twice the mass of all the other planets combined.

9. 9Which organ pumps blood around the body?Answer

   The heartIt beats roughly 100,000 times a day.

10. 10At what temperature in Celsius does water boil at sea level?Answer

    100 °CThat is 212 °F. At high altitude it boils at a lower temperature.

11. 11What is the center of an atom called?Answer

    The nucleusIt holds the protons and neutrons and nearly all of the atom's mass.

12. 12Which planet is closest to the Sun?Answer

    MercuryEven so, Venus is hotter, thanks to its thick carbon dioxide atmosphere.

13. 13What do bees collect from flowers to make honey?Answer

    NectarThey evaporate most of its water inside the hive to thicken it.

14. 14What force keeps the planets in orbit around the Sun?Answer

    GravityThe same force that keeps your feet on the ground.

1. 15What is the most abundant gas in Earth's atmosphere?Answer

   NitrogenIt makes up about 78% of the air; oxygen is about 21%.

2. 16Which part of the cell is often called its powerhouse?Answer

   The mitochondriaThey even carry their own small set of DNA.

3. 17Who developed the theory of general relativity?Answer

   Albert EinsteinHe published it in 1915; it describes gravity as curved spacetime.

4. 18Roughly how fast does light travel in a vacuum?Answer

   About 300,000 km per secondLight from the Sun takes a little over eight minutes to reach us.

5. 19Which element has atomic number 1?Answer

   HydrogenIt is the most abundant element in the universe.

6. 20What is the largest organ of the human body?Answer

   The skinIn an adult it covers about two square meters.

7. 21Who created the first successful smallpox vaccine?Answer

   Edward JennerIn 1796 he used material from cowpox to protect against smallpox.

8. 22What is the only metal that is liquid at room temperature?Answer

   MercuryIt freezes at about −39 °C.

9. 23What is the scientific study of earthquakes called?Answer

   SeismologySeismometers record the waves that earthquakes send through the planet.

10. 24How many chromosomes do most humans have?Answer

    46They come in 23 pairs, one of each pair from each parent.

11. 25What does DNA stand for?Answer

    Deoxyribonucleic acidIts double-helix structure was described in 1953.

12. 26What is the pH of pure water?Answer

    7That is neutral; lower is acidic and higher is alkaline.

13. 27Who discovered penicillin?Answer

    Alexander FlemingIn 1928 he noticed mold killing bacteria in a forgotten dish.

14. 28Which blood type is known as the universal donor for red blood cells?Answer

    O negativeIt can be given to patients of any blood type in an emergency.

1. 29What is the most abundant element in Earth's crust?Answer

   OxygenIt makes up nearly half the crust by mass, mostly locked in rocks; silicon is second.

2. 30Which subatomic particle has no electric charge?Answer

   The neutronJames Chadwick discovered it in 1932.

3. 31Which planet spins almost on its side?Answer

   UranusIts axis is tilted about 98 degrees.

4. 32What is absolute zero in degrees Celsius?Answer

   −273.15 °CIt is the lowest possible temperature, 0 on the Kelvin scale.

5. 33Which metal has the highest melting point?Answer

   TungstenIt melts at about 3,422 °C, which is why it was used for light-bulb filaments.

6. 34What word describes animals that are most active at dawn and dusk?Answer

   CrepuscularRabbits, deer, and many cats fit the description.

7. 35Who worked out that planets move in elliptical orbits?Answer

   Johannes KeplerHe published his laws of planetary motion in the early 1600s.

8. 36What is the SI unit of electrical resistance?Answer

   The ohmIt is named after the German physicist Georg Ohm.

9. 37Which organ produces insulin?Answer

   The pancreasClusters of cells called the islets of Langerhans make it.

10. 38What is the chemical symbol for potassium?Answer

    KIt comes from kalium, the element's Latin name.

11. 39What is the nearest large spiral galaxy to the Milky Way?Answer

    The Andromeda GalaxyIt is about 2.5 million light-years away and visible to the naked eye on dark nights.

12. 40Which mineral ranks 1, the softest, on the Mohs hardness scale?Answer

    TalcDiamond sits at the top, at 10.