Science questions for curious minds
Why does ice float? Why is Venus hotter than Mercury? How long does sunlight take to reach us? Our science quiz covers chemistry, astronomy, physics, plants and the human body, with questions you may remember from school and a few that might surprise you.
The Yes or No questions go after popular myths, like the idea that we only use 10% of our brains or that glass is a slow-moving liquid. After every answer you see the correct one and the fact behind it.
Science trivia questions with answers
What is the most common gas in Earth's atmosphere?
Nitrogen. It makes up about 78% of the air we breathe; oxygen is about 21%.
What is the largest organ of the human body?
Skin. In an adult it covers about 20 square feet (2 m²); the liver is the largest internal organ.
Sound travels fastest through which of these?
Steel. Sound moves about 17 times faster in steel than in air, because the particles are packed closer together.
Is lightning hotter than the surface of the Sun?
Yes. A lightning bolt can heat the air to about 50,000 °F (28,000 °C), around five times hotter than the Sun's surface.
Is glass a liquid that flows very slowly?
No. Glass is an amorphous solid. Old windows that are thicker at the bottom were simply made that way, or installed that way.
Is Earth closer to the Sun in January than in July?
Yes. Earth reaches its closest point, called perihelion, in early January. Seasons depend on the tilt of Earth's axis, not on distance.
More science questions
What is the chemical symbol for iron?
Fe, from the Latin word for iron, ferrum.
What is the hardest natural substance on Earth?
Diamond. It's made only of carbon atoms, locked together in a very strong crystal structure.
How fast does light travel?
About 186,000 miles (300,000 km) per second. Nothing in the universe travels faster.
At what temperature does water freeze on the Fahrenheit scale?
32 °F, which is 0 °C.
Who developed the theory of relativity?
Albert Einstein. He published special relativity in 1905 and general relativity in 1915.
Two ways to play
- Classic: one question, four answers, and every second counts toward your grade.
- Yes or No: true or false statements, including the science myths that fool almost everyone.
Frequently asked questions
What topics does the science quiz cover?
Chemistry, astronomy, physics, plants and the human body, in twenty quizzes: twelve Classic and eight Yes or No.
Is the science quiz free?
Yes. You can play it all without signing up; a free account saves your score.
Is it good for studying?
Yes. Every answer comes with a short explanation, so it works well as a quick review of what you learned at school.
Where to go next
Move on to the animal quiz, or try the General Knowledge Quiz for questions from nineteen different subjects. Scoring, timers and hints are explained in the quiz guide.