The correct answer is option 'B', which states that the Earth's atmosphere is composed of 78% nitrogen, 21% oxygen, and 1% other gases.

Explanation:

Composition of Earth's atmosphere:

The Earth's atmosphere is composed of different gases and particles that surround the planet. The atmosphere is divided into different layers based on their physical and chemical properties. The composition of the atmosphere is given below:

1. Nitrogen (N2) - 78%

Nitrogen is the most abundant gas in the Earth's atmosphere. It is a colorless, odorless, and tasteless gas that exists as a diatomic molecule (N2). Nitrogen is an essential element for all living organisms and is important for the growth of plants.

2. Oxygen (O2) - 21%

Oxygen is the second most abundant gas in the Earth's atmosphere. It is a colorless, odorless, and tasteless gas that exists as a diatomic molecule (O2). Oxygen is essential for the survival of most living organisms, including humans.

3. Other gases - 1%

The remaining 1% of the Earth's atmosphere is composed of different gases such as argon (0.93%), carbon dioxide (0.04%), neon (0.0018%), helium (0.0005%), methane (0.0002%), krypton (0.0001%), hydrogen (0.00005%), and xenon (0.000009%).

Importance of Earth's atmosphere:

The Earth's atmosphere plays a vital role in supporting life on the planet. It protects the Earth from harmful radiation and solar winds, regulates the temperature, and provides the necessary gases for the survival of living organisms. The composition of the atmosphere also affects the climate, weather patterns, and air quality.

Conclusion:

The Earth's atmosphere is composed of 78% nitrogen, 21% oxygen, and 1% other gases. The composition of the atmosphere is essential for supporting life on the planet and regulating the climate and weather patterns.