Water and Its Properties
What is chemical formula of water?
H2O
Where is most of Earth’s water found?
In the oceans.
What process changes water from liquid to gas?
Evaporation.
Give two uses of water in daily life.
Drinking, cooking, cleaning, watering plants, generating electricity…
Give two simple actions to save water at home.
Turn off the tap when brushing teeth, take short showers, reuse rainwater.
Why does ice float on water?
Because solid water is less dense than liquid water.
What percentage of Earth’s water is fresh water?
About 3%.
What happens to water vapor when it cools down?
It condenses and forms clouds.
What is water pollution?
When harmful substances get into water and change its composition, making it unsafe.
What does “sustainable use of water” mean?
Using water in a way that protects it for future generations.
What does it mean that water is a universal solvent?
It can dissolve many substances, like salt or oxygen.
Name three places where we can find fresh water.
Glaciers, rivers, lakes, underground aquifers…
What is precipitation?
When water falls from the sky as rain, snow, or hail.
Name two main causes of water pollution.
Factories, farms, livestock, plastics...
What is the purpose of a water treatment plant?
The purpose of a water treatment plant is to elliminate particles and pollutants from the water, so it´s safe for us to drink.
What property of water allows the ocean to be a climate regulator?
Water can store heat (high thermal capacity)
Fresh water is called fresh because it does not contain any dissolved salts. True or
False?
False. It actually contains many different dissolved salts (but less than salt water).
What process defines the flow of water between the mountains and the sea?
Run off (it can be above or below the surface).
What is eutrophication and why is it dangerous?
Eutrophication is the excessive enrichment of nutrients in an aquatic ecosystem, due to human activities such as the use of fertilisers. This excess of nutrients causes massive growth of algae and aquatic plants (algal blooms), which reduces the light reaching the deeper layers and can lead to the death of plants and fish.
What is the purpose of a purification (wastewater treatment) plant?
Its purpose is to clean dirty or polluted water so it can be safely returned to the environment or reused.