(i) Using beakers, the mustard oil is separated by the process of decantation, because oil being lighter than water, floats on water.
(ii) Next filtration is using a funnel and filter paper and thus water gets separated from chalk powder and coins.
(iii) By hand-picking method, the coins are separated frorn chalk powder.

(i) By churning the curd, the solid butter will be collicted on the sides of the vessel.
(ii) The insoluble butter will be separated from the buttermilk and thus the buttermilk will be obtained.

(i) By winnowing a large quantity of tiny bits of paper mixed with pulses.
(ii) As paper is lighter than pulses, they can be easily separated by winnowing.

The method of separation is sieving.
(i) sieving is used when we have to separate solid particles of different sizes.
(ii) In this picture, the flour is separated from the targer sized particles.

(i) The atoms of a gas never stop moving.
(ii) They are not affected by gravity.
(iii) They spread out in order to occupy the available space.

(i) Yes, a rubber ball can be called a solid because it doesn't flow away like liquids or gases.
(ii) But the rigidity of the rubber ball is less than the external force. So it changes its shape.

The settling down of heavier component of a mixture when allowed to remain undisturbed for some time is called sedimentation.

Lemon juice is a mixture because it is a miture of lemon extract, water and sugar.  This is a mixture though the amount of sugar and water added is different we know that, in a mixture the components are mixed in any proportion.

We have to separate mixture,
(i) to remoe impurities
(ii) to separate useful components
(iii) to get a highty pure form substance

Matter is defined as anything that has mass and takes up space.