Page 131 - ICSE Chemistry 6

5. Write the elements present in the following compounds and give one use of each compound.

Compound Elements present Use

Ammonia

Common salt

Carbon dioxide

Sodium hydroxide

Sand

Water

6. Represent the following diagramma cally.
(a) Nitrogen molecule

(b) Water molecule
(c) Ozone molecule

(d) Carbon dioxide molecule

Now answer the following ques ons.
(a) Write the formulae of the given molecules.
(b) How are the atoms of diff erent elements combined in a molecule?

(c) How are the atoms in a molecule held together?

7. Ananya wants to know why it is that in a mixture, original atoms and molecules remain as they are. Help
her to reason this out with the help of an example.
8. Write the methods of separa on used to separate the following mixtures. State the principle on which
these methods of separa on are based upon.

Mixture Separa on method Principle

Stones and pebbles in sand

Insoluble substances and water

Iron and sulphur

Sodium hydroxide

Salt from sea water

Pulp from fresh juice

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