Give reasons for the following statements:

1. Components in a mixture can be separated by physical methods only.

2. Centrifugation can be used for separating an insoluble heavier solid, present in an insoluble solid-liquid mixture.

3. The filter paper made into a cone & placed in a funnel for filtering out the solid particles in a solid-liquid mixture, should be moistened before placing.

4. Brass & bronze are examples of mixtures, while copper sulphate & lead nitrate are examples of compound.

5. Zinc is considered an element, while zinc sulphide is considered a compound.

1. A mixture is made by mixing two or more substances mixed mechanically and the components retain their original properties, hence, components in a mixture can be separated by physical methods only.

2. Centrifugation is used for separating an insoluble heavier solid, present in an insoluble solid-liquid mixture as more dense component migrates away from the axis of the centrifuge and less dense component migrates towards the axis of the centrifuge. Hence, the two components can be separated.

3. On moistening the filter paper cone, it sticks to the walls of the funnel and makes filtration easy.

4. Brass & bronze are examples of mixtures as the components are mixed together mechanically and the components retains their original properties. Copper sulphate & lead nitrate are examples of compounds as the components are combined chemically in fixed proportions and they do not retain their original property.

5. Zinc is considered an element as it is made up of one kind of atoms only, while zinc sulphide is considered a compound as it is made up of two elements [zinc and sulphur] combined in a fixed proportion.