Page 78 - Active Science 5 Ebook and Activity

7. Water is a neutral substance. It is neither acidic nor basic.

8. It is a universal solvent. Almost anything can be dissolved in it. When a substance

dissolves fully in a solvent, a solution is formed. The substance is said to be soluble.

Let’s Recapitulate

Fill in the blanks.
1. Water is very essential for ______________ of life.

2. ______________ is the main source of water on earth.
3. Water is a universal ______________.

4. ______________ water is fit for human consumption.

Factual Study
Water Table
When it rains, the rain water goes into rivers, streams, ponds and lakes. Some of the water penetrates
the porous layers of the earth to reach the non-porous layers. This is called underground water
and its level is called water table. The water table rises during the rainy season but drops down
during summer.
Since the number of people has increased and people are digging out ground water faster than it can
form, the water table is sinking deeper and deeper. Nowadays, the government and local bodies are

encouraging rainwater harvesting projects to raise the water table.

R emoving Insoluble Substances from Water

There are two methods of removing insoluble substances from water, i.e., filtration,

sedimentation or decantation.

1. Filtration: Filtration is a process to separate insoluble solid substances from liquids
by passing the mixture through a filter.

Activity 6.5

Aim : To demonstrate the process of filtration.
Materials Required: A funnel, a filter paper, two containers, water, any
insoluble material.
Procedure : • Take a container filled with water.
• Put some sand in it.

• Now take a funnel.
• Now take another container.
• Pour the water containing the insoluble Filtrate

solid substance into another container using a funnel.
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