Mass:

(i) The mass of an object is the quantity of the matter contained in it.

(ii) The SI unit of mass id kilo-gram (kg).

(iii) The mass of an object is constant.

(iv) The mass of an object can never be zero.

Weight:

(i) The weight of an object is the force with which it is attracted towards the centre of the earth.

(ii) The SI unit of weight is Newton (N).

(iii) The weight of an object is variable. It changes with the change in acceleration due to gravity.

(iv) The weight of an object can be zero.