Question

Q2. Define:
(a) Atmosphere (b) wind and (c) humidity​

Answer 1

Answer:

1. Atmosphere:

The atmosphere is the blanket of gases which surrounds Earth. It is held near the surface of the planet by Earth's gravitational attraction.

Without the atmosphere there could be no life on Earth. The atmosphere:  

• contains the air we breathe;

• protects life from harmful radiation from the Sun;

• helps keep the planet's heat from the Sun from escaping back into space;

• is a major element of the water cycle;

• keeps the climate on Earth moderate compared to that of other planets.

The atmosphere is made up of a mixture of gases, mostly nitrogen, oxygen, argon and carbon dioxide. It reaches over 500km above the surface of the planet. There is no exact boundary between the atmosphere and outer space. Atmospheric gases become thinner the higher up you go. The atmosphere just keeps getting less and less dense, until it "blends" into outer space.

2. Wind:

Wind is the movement of air, caused by the uneven heating of the Earth by the sun and the Earth's own rotation. Winds range from light breezes to natural hazards such as hurricanes and tornadoes.

3. Humidity

Humidity is the presence of water vapor in the atmosphere. The more water evaporates in a given area, the more water vapor rises into the air, and the higher the humidity of that area is. Hot places tend to be more humid than cool places because heat causes water to evaporate faster.

Explanation: