1. Which gas is most abundant in the Earth’s atmosphere?
2. What is the chemical formula of water?
3. Which part of the plant conducts photosynthesis?
4. The unit of electric current is?
5. Which planet is known as the Red Planet?
6. Which vitamin helps in blood clotting?
7. What is the hardest natural substance?
8. Sound travels fastest in?
9. Which organ purifies blood in the human body?
10. What is the boiling point of water at sea level?
11. Which metal is liquid at room temperature?
12. Which force pulls objects toward Earth?
13. Which gas do plants absorb during photosynthesis?
14. The human heart has how many chambers?
15. Which planet is the largest in the solar system?
16. The SI unit of work is?
17. Which blood group is universal donor?
18. What is the main source of energy for Earth?
19. Which instrument measures atmospheric pressure?
20. Which part of the cell contains genetic material?
