Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Water is essential for all living beings; nearly or of the Earth's surface is covered with water.
Rain is the primary source of water on Earth. It fills rivers, lakes, ponds, and oceans.
Surface water includes water bodies like rivers, lakes, and seas. Ocean water contains high amounts of salt and is not fit for drinking.
Groundwater is water that seeps into the soil and is stored underground. It can be accessed using , , or .
The chemical notation for a water molecule is .
Domestic uses of water include drinking, cooking, bathing, and washing clothes.
Agricultural use includes irrigation, which is the artificial application of water to the soil for growing crops.
Industrial uses involve using water in factories for manufacturing goods and cooling machinery.
📐Formulae
💡Examples
Problem 1:
If a person drinks liters of water every day, how much water will they drink in a week ( days)?
Solution:
Explanation:
This demonstrates a daily domestic use of water for maintaining health.
Problem 2:
Identify the source: A farmer uses a machine to pull water from deep under the ground to water his crops. What is this source called?
Solution:
Tube well (Groundwater source)
Explanation:
Water that collects under the earth's surface is called groundwater, and a tube well is a common way to extract it for irrigation.
Problem 3:
Why can't we use water from the sea to cook our food?
Solution:
Because sea water is saline ().
Explanation:
Seas and oceans contain dissolved salts, making the water unfit for domestic purposes like cooking or drinking.