The normal body temperature of a healthy human is approximately:

Rusting of iron is an example of which type of reaction?

Which vitamin is produced in human skin upon exposure to sunlight?

The pH value of pure water at room temperature is:

The process by which plants lose water in the form of vapor is called:

Sound cannot travel through:

The hardest natural substance found on Earth is:

The energy released when a substance burns in the presence of oxygen is called:

The chemical formula for common table salt is:

Which of these is not a renewable source of energy?

The study of heredity and variation in living organisms is called: