True.
For example: Sodium oxide and Nitric acid; both compounds contain oxygen.
Answer: 10 uses
Explanation:
1] Oxygen is used for breathing.
2] Chlorine is used for purifying water.
3] Phosphorous is used in crackers.
4] Non - metals like nitrogen is used in fertilizers.
5] Graphite is used as a good conductor of electricity.
6] Pottassium is used in fertilizers.
7] Nitrogen is used by plants.
8] Graphite is used in making leads.
9] Carbon is used as a fuel.
10] Bromine is used in dyes and pesticides
b) law of conservation of energy