I. Additional Questions and answers :
1) A lemon sinks in glass of plain water but floats on adding salt in the water. Why.
Ans : A lemon sinks in a glass of plain water but floats on adding salt in the water because water become thicker (sense) on adding salt.
2) Why does a person floats in died sea even after he does not know how to swim.
Ans : A person floats in dead sea even after he dies does not know how to swim because dead sea is the saltiest of all .
3) Suggest some ways to quickly dissolve in sugar water for making shakkarpara .
Ans :Following are the two ways to quickly dissolve sugar in water for making Shakkarpara:
i) Stir the mixture of sugar and water thoroughly.
ii) Warm the mixture over flame.
4) State the mixture of sugar and water called.
Ans: A mixture in which a substance has fully dissolved in water is called a solution. And the substances is said to be soluble. An example of this type of mixture is sugar in water. Here the dissolves fully to give a clear solution.
5) Do you think that the oil gets dissolved in water why do you think so.
Ans : No, the oil does not get dissolved in water oil always floats on water this happens because water molecules are more attracted to each other than oil molecules.
6) How the salt is made.
Ans : The sea water is collected in shallow beds dug in sand.Water is allowed to dry in the sun. Salt remains on the ground after the water is dried.
II. Fill in the blanks :
1. For making salt water is allowed to dry in ___________.
2. Dead seas is the _____________of all.
3. Common salt is ________in water while chalk powder does not dissolve in water .
4. Iron nail sinks in water but the katori______________ .
Answers :
1. Sun 2. Saltiest 3. Soluble 4. Floats .
III. Match the columns :
| A | B |
| Oil and water | Floats on sugarcane juice |
| Piece of ice | Sinks in water |
| Empty plastic bottle | Do not mix |
| Bottle full of water | Floats on water |