Q1Written answer
From where do you get your drinking water? A river or a lake?
Show solutionHide solution
Worked solution
I get drinking water from a river.
NCERT · Class 4 · EVS
Chapter 13: A River’s Tale
Practice each question, then open the answer or worked solution.
How does Water become Dirty?
12 questionsQ2Written answer
Do you think that like the river in the picture, your river or lake can also be affected?
Show solutionHide solution
Worked solution
Yes, the river located in my town is affected by pollution.
NCERT Textbook Page No. – 111
Q3Written answer
Fill about half of each bottle or glass with water. Make sure that all have the same amount of water. Now, one by one, put each of the things in the water. For example – haldi in the first glass, oil in the second glass, and soda in the third glass until you have one thing in each glass. Mix each thing in the water and see what happens. Write your observations in the table. What did you observe? Put (✓) mark in the right places.
Show solutionHide solution
Worked solution
NCERT Textbook Page No. – 111
Now, on the basis of your observations, tell.
Q4Written answer
Do all things dissolve in water?
Show solutionHide solution
Worked solution
No, all things do not dissolve in water.
Q5Written answer
Does the colour of the water always change?
Show solutionHide solution
Worked solution
No, the colour of the water does not always change.
Q6Written answer
Did oil dissolve in water? How can you say whether it has dissolved or not?
Show solutionHide solution
Worked solution
No, oil does not dissolve in water. Things which are insoluble in water either come up or settle down.
For example, oil floats on water.
Q7Written answer
Colour of the water may not change even after some things are dissolved in it. Would you say that these are absent in water?
Show solutionHide solution
Worked solution
Things which are dissolved in water are always present in the water.
Q8Written answer
Imagine how it would be if things like sugar, salt, lemon juice, sherbet, etc., could not dissolve in water!
Show solutionHide solution
Worked solution
If things like sugar, salt, lemon juice, sherbet, etc., could not dissolve in water, cooking food and preparing things like cold drinks, coffee, tea, etc., will not be possible.
Q9Written answer
Imagine how it would be if things like stones, chalk, plastic and garbage would dissolve in water!
Show solutionHide solution
Worked solution
If things like stones, chalk, plastic and garbage would dissolve in water, they would make the water dirty.
Q10Written answer
How is drinking water cleaned in your house?
Show solutionHide solution
Worked solution
The drinking water in our house is cleaned using a water filter.