Question

a) Explain with the help of an activity that particles of matter are very small.
(b) Define matter. Name the states of matter in which the forces between the constituent particles are :
(i) strongest
(ii) weakest
(c) When sugar and common salt are kept in different jars, they take the shape of the jars. Are they solid ? Justify your answer.

CBSE Class IX Science LA (5 Marks)

Answer 1

(a) Activity :

(i)     Take 2 -3 crystals of copper sulphate and dissolve them in 100 ml of water.

(ii)   Take out approximate 10 ml of this solution and put it into 90 ml of clear water.

(iii) Take out 10 ml of this solution and put it into another 90 ml of clear water.

(iv)  Keep diluting.

Observation : A crystal of copper sulphate contains millions of tiny particles which keep on dividing into smaller and smaller number with each dilution.

Inference : This activity shows that particles of matter are very small.                                  

(b) Matter : Anything which possesses mass and occupies space is called matter.                                

(i) Solid - strongest,

(ii)   Gas  - weakest.                                                         %+%

(c) The shape of each individual sugar or salt crystal remains fixed, therefore they are solids.