Science Facts Recall
1 / 15Test your recall of important science facts!
15 quick questionsNo sign-upFree to playTap an answer below to begin ↓
What is the chemical formula for water?
About Science Facts Recall
Give your memory a workout with Science Facts Recall: 15 multiple-choice questions with a mix of 5 easy, 5 medium, 5 hard questions, free to play right in your browser. Test your recall of important science facts! Expect to spend about 7 minutes; every question comes with an explanation, so you learn something even when you miss.
A few sample questions
1. What is the chemical formula for water?
Answer: H2O
Water's chemical formula is H2O, meaning each molecule contains two hydrogen atoms and one oxygen atom.
2. What planet is known as the 'Red Planet'?
Answer: Mars
Mars is called the Red Planet because iron oxide (rust) on its surface gives it a distinctive reddish appearance.
3. What gas do plants absorb from the atmosphere during photosynthesis?
Answer: Carbon dioxide
Plants absorb carbon dioxide (CO2) and use sunlight to convert it into glucose and oxygen through photosynthesis.
4. How many planets are in our solar system?
Answer: 8
There are 8 planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto was reclassified as a dwarf planet in 2006.
5. What is the hardest natural substance on Earth?
Answer: Diamond
Diamond is the hardest natural substance on Earth, rating 10 on the Mohs hardness scale. It is made of carbon atoms arranged in a crystal structure.
Things you'll learn along the way
- The skin is the largest organ, covering about 20 square feet in adults and weighing about 8 pounds. It serves as the body's first line of defense.
- Light travels at approximately 186,000 miles per second, which equals about 670 million miles per hour. Both expressions describe the same speed.
- Fe is the chemical symbol for iron, derived from its Latin name 'ferrum.' Iron is essential for making hemoglobin in red blood cells.
Frequently asked questions
How long does Science Facts Recall take?
Most players finish Science Facts Recall in about 7 minutes. You can pause between questions, replay it as often as you like, and there is no penalty for taking your time — answers are explained after you submit them.
What's a good follow-up after Science Facts Recall?
If you enjoyed this memory games quiz, try the Daily Challenge — five rotating questions, refreshed every 24 hours, that count toward your streak. You can also use the Surprise Me button on the homepage to land on a different game type for variety.
Can I print Science Facts Recall?
Yes — use the Print button at the top of the page for a clean question sheet, or "Print with Answers" to make an answer key. Printed sheets work well for group play at home, in a classroom, or at a senior center.
Will I lose my progress if I close the page?
Your overall progress — XP, streaks, and badges — is saved in your browser automatically. A quiz that's underway restarts if you leave mid-game, but at about 7 minutes, Science Facts Recall fits comfortably in one sitting.
Explore related topics
More Memory Games
Earth Science Quiz
From tectonic plates to the water cycle, test your recall of Earth science concepts and geological facts.
Amazing Animal Facts Quiz
Test your knowledge of the animal kingdom's most surprising record-holders — from the fastest creature on Earth to the one that never stops growing!
Astronomy Facts Recall
Explore the cosmos with this quiz! Test your recall of stars, planets, galaxies, and space phenomena.
Brain Facts
Test your knowledge about the human brain and how it works!
Dinosaur Facts Quiz
Match dinosaurs to their characteristics and era
Try General Knowledge
Science True or False
Is this science fact true or false? Test your scientific knowledge!
Try General Knowledge
Animal Kingdom Facts
Interesting and surprising animal facts
From our guides
Memory Games for Seniors
How memory games help, and which ones to start with.