(A) In a gas, spaces between the molecules are large and interaction between the molecules is low. Hence, it is easier to compress them by applying pressure
(B) The intermolecular force is weaker than that of solids in liquids. Hence, molecules in a liquid can slip over one another and liquids can flow, unlike solids
(C) In order to distinguish, we need to classify things. In this way, things can be categorized and can be easily studied.
(D) Pure substances consist of only one kind of matter. All the particles of a pure substance are alike. It has a definite composition and similar properties. Due to this reason pure substances have fixed melting or boiling points.
(E) Electricity neither has mass nor occupies space. Besides, it can not be seen by our eyes. Hence, electricity is not considered a matter.