Define :
(a) Elements
(b) Compounds
(a) Elements: Element is a substance which cannot be broken further into simpler substances and has
a definite set of properties. Elements are made up of only one kind of atoms. e.g Na , H , Cu
(b) Compounds: Compounds are pure substances composed of two or more elements in definite proportion by mass and has properties, entirely different from those of its constituents elements.Compound, are made up of different types of atoms combined chemically. e.g NaCl , CaCO3