What is the chemical symbol for water?

What gas do humans breathe in to survive?

Which part of the plant makes food using sunlight?

Who proposed the theory of relativity?

What is the hardest natural substance found on Earth?

Which blood group is called the universal donor?

Which vitamin is produced in the body when exposed to sunlight?

What force keeps the planets in orbit around the Sun?

Which organ in the human body is responsible for pumping blood?

What is the boiling point of water at sea level?