Water Vapor

Water vapor is the gaseous state of water. It is an invisible gas that is formed when water evaporates. When water is heated, it changes from a liquid to a gas and becomes water vapor. This process is called evaporation.

Properties of Water Vapor

• Invisible: Water vapor is invisible to the naked eye, unlike liquid water.
• Lightweight: Water vapor is lighter than air, which allows it to rise into the atmosphere.
• Expands when heated: Like all gases, water vapor expands when it is heated and contracts when it is cooled.

Formation of Water Vapor

Water vapor is formed through the process of evaporation. When the sun heats the surface of water bodies such as oceans, lakes, and rivers, water molecules gain enough energy to break free from the liquid and become water vapor. This water vapor then rises into the atmosphere.

Importance of Water Vapor

Water vapor plays a crucial role in the Earth's water cycle. It is a major component of the atmosphere, and when it condenses, it forms clouds and precipitation. Water vapor also helps regulate the Earth's temperature by trapping heat in the atmosphere, contributing to the greenhouse effect.

Study Guide

1. What is water vapor?
2. How is water vapor formed?
3. What are the properties of water vapor?
4. Explain the importance of water vapor in the Earth's water cycle.

For further understanding, students can conduct experiments to observe the process of evaporation and condensation, and how water vapor interacts with the atmosphere.