Les. 4 & 5 - Water  Safe for Drinking & Every Household

     Q1. Answer the following :

      1. What is known as potable water?

Ans. Water that does not endanger our health in any way when we drink it is called safe drinking water or potable water.

2.   Name the instrument used for looking at micro

organisms?

Ans. Micro-scope is used for looking at micro-organisms.

3.   What is settling?

Ans. The process of allowing heavier particles to settle to the              bottom of still water is called settling.

4.    What steps can be taken to take care of drinking water?

Ans. a)We can keep drinking water containers covered.

         b) making use of a dipper to take out water.

         c) we must put a tap on the container to take water.

         d) we must wash the container well before refilling                       water.

II. Classify the following substances accordingly:

   1.   Syrup       Plastic bottle      iron nail                      oil

   2.  Leaf         honey                  sand                      brick

   3.  coin          ball                       lemon juice            shells

Substances that dissolve	Substances that do not dissolve	Substances that float	Substances that sink
1.   Syrup	Oil	Plastic bottle	Iron nail
2.  honey	Sand	Leaf	Brick
3.  lemon juice	Shells	Ball	Coin

III. Distinguish between:

1. Soluble and Insoluble substances

Soluble substances	Insoluble substances
1. Substances which dissolve in water are known s soluble substances	1. Substances which do not dissolve in water are known s soluble substances
2. Example – sugar, salt	2. Example – wood, stone

Storage of Water

Q.1 Answer the following questions in one word:

1. The main source of water on the earth.- rain

2. The traditional method of water storage in cities.- tanks

3. The traditional method of drinking water storage.- draw well

Q.2 Answer the following questions:

1. Where do water stores like rivers, dams, wells and lakes get their water from?

Ans. Water stores like rivers, dams, wells and lakes get their water from rain.

2. What is a dam built on?                                                                 Ans. A dam is built on a river.

3. What must we keep in mind while using water?

Ans. Water is a natural resource. Along with us, all living beings use water all year around. In our country, rainy season lasts only for three or four months. If we do not store water we will face a problem of shortage of water. Therefore we should we store water.

4. What is water pollution?                                                                    

Ans. A fall in quality of water is known as water pollution. Waste water from houses, factories get mixed in rivers, lakes etc. This result in water pollution.

Q.3 Complete the sentences:

1. All the water we get comes from the rain.

2. When tap system was introduced the draw wells went out of use.

3. Draw wells were dug to get drinking water.

4. Bore-wells are dug to draw deep seated ground water.

Day and Night

I.  Answer the following questions.

1. When do we say that it is day time?

Ans: We say that it is day time when we get light from the              sun.

2. What is rotation of the earth?

Ans: The spinning of the earth around itself is known as the            rotation of the earth.

3. What is revolution?

Ans: The spinning of the earth around the sun is called as                revolution.

4. When is it summer?

Ans: When the days are longer and the nights are shorter it is           summer.

5. When is it winter?

Ans: When the days are shorter and the nights are longer it is           winter.

II State whether True or False:

1. The number of hours in the day and night on   

     22nd March are equal -True  

2. In our part of the earth, on the 22nd June, the day is   the longest and the night is the shortest -True 

3.On 22nd September the length of the day and the night are unequal -False      

4. In our part of the earth,  on 22nd  December, the day is longest and the night is the shortest – False

5. The earth gets its light from the sun. – True

6. We say that it is night when we do not get light from the sun. – True