Water is a combination of:

Question

Water is a combination of:

1. A. Oxygen & Hydrogen (Correct answer)
2. B. Oxygen & Nitrogen
3. C. Chlorine & Hydrogen
4. D. Nitrogen & Oxygen

Correct Answer

Option A — Oxygen & Hydrogen

Detailed Solution & Explanation

The correct answer is Oxygen & Hydrogen.

Key Points

• Water is H₂O — a compound of hydrogen and oxygen, in the ratio of two hydrogen atoms to one of oxygen.
• By mass the ratio is 1 : 8, hydrogen to oxygen.

Additional Information

• The molecule is bent, with a bond angle of about 104.5°, making it polar — the reason water dissolves so many substances and is called the universal solvent.
• Hydrogen bonding between molecules explains water's high boiling point, high surface tension and the fact that ice floats, being less dense than liquid water.
• Water is densest at 4°C, which is why lakes freeze from the top down and aquatic life survives beneath.