All questions of States of Water for Class 6 Exam

Evaporation is the process where liquid water changes into vapor due to heat.

Water covers most of the Earth and is essential for all living beings to survive.

Cooling water below 0°C causes it to freeze and turn into ice.

Water exists in three states—solid (ice), liquid (water), and gas (water vapor). Plasma is not a state of water.

Understanding Evaporation
Evaporation is the process where liquid turns into vapor. Several factors influence the rate of evaporation, and one of the most significant is the surface area of the liquid.
Why Larger Surface Area Increases Evaporation
- More Molecules Exposed: When the surface area of a liquid is larger, more molecules are exposed to the air. This means that more molecules have the opportunity to escape into the vapor phase.
- Greater Energy Absorption: A larger surface area allows for more energy absorption from the surrounding environment. This additional energy helps more molecules reach the necessary speed to break free from the liquid.
- Enhanced Interaction with Air: With a larger area, there’s an increased interaction between the liquid and the air. This leads to a greater chance of molecules transitioning into vapor.
Comparison with Other Factors
- Lower Temperature: Lower temperatures reduce the kinetic energy of molecules, leading to slower evaporation rates.
- Higher Humidity: Increased humidity means the air is already saturated with water vapor, which slows down the evaporation process as fewer molecules can escape into the air.
- Less Airflow: While airflow can enhance evaporation by moving vapor away from the liquid surface, it does not compensate for the lack of surface area.
In summary, having a larger surface area significantly increases the rate of evaporation by allowing more molecules to escape into the air, making it a key factor in this process.

Water vapor in the air cools and condenses into liquid droplets on the cold bottle.

Understanding the Process of Condensation
When water changes from a gas to a liquid, the process is known as condensation. This is an essential concept in the water cycle and plays a significant role in weather patterns.
What is Condensation?
- Condensation occurs when water vapor in the air cools down and transforms back into liquid water.
- This process is vital for the formation of clouds, fog, and dew.
How Does Condensation Happen?
- Cooling of Air: When warm air rises, it expands and cools. As it cools, it can no longer hold as much moisture.
- Water Vapor Collection: The excess water vapor begins to clump together, forming tiny droplets of liquid water.
- Visible Effects: These droplets aggregate to form clouds or dew on surfaces, such as grass or cars.
Importance of Condensation
- Weather Formation: Condensation is crucial for creating precipitation, such as rain or snow, which is essential for replenishing water sources on Earth.
- Climate Regulation: It helps to maintain temperature and humidity levels in the atmosphere, influencing our climate.
Conclusion
In summary, condensation is the process by which water vapor in the air turns back into liquid water, playing a critical role in the water cycle and various environmental phenomena. Understanding this process helps us grasp the dynamics of weather and climate.

Wind increases air movement, which speeds up evaporation and helps dry clothes faster.

Water helps in digestion, regulates body temperature, and is essential for all life processes.

The Cooling Effect of Evaporation
Evaporation is a natural process that occurs when liquid turns into vapor. This process plays a crucial role in cooling the surroundings.
How Evaporation Works
- When water evaporates, molecules at the surface gain enough energy to break free from the liquid state and enter the air as gas.
- This energy is taken from the water itself, resulting in a decrease in the temperature of the water.
Heat Absorption
- During evaporation, heat energy is absorbed from the surrounding environment.
- This process is why sweating cools our skin; as sweat evaporates, it absorbs heat from our body, making us feel cooler.
Examples of Cooling Effect
- Sweating: When we sweat, the moisture on our skin evaporates, cooling us down.
- Cooling of Water Bodies: Large bodies of water, like lakes and oceans, experience evaporation, which helps maintain cooler temperatures, especially during hot weather.
Conclusion
- Thus, evaporation effectively absorbs heat, leading to a cooler environment, which is why the correct answer is option 'B'.
- Understanding this concept helps us appreciate the role of evaporation in weather patterns and everyday life.

An AWG extracts moisture from air and converts it into drinkable water.

The heat of the pan converts water into steam, which is water in gaseous form.

Ice and water are both forms of the same substance, H₂O, but in different states (solid and liquid).

Humidity measures how much water vapor is present in the air.

Water in a glass is in a liquid state as it flows and takes the shape of its container.