Dear student,
(a) Atoms are building blocks of all matter. They are the smallest particles of elements that can take part in a chemical reaction. Atoms generally exist as molecules of elements and molecules of compounds.
(b) A molecule is made up of atoms and it is the smallest particle of a substance which has the properties of that substance.
Example: Oxygen atoms combine to form O3 molecules
(c) Molecule of an element consists of two or more atoms of the same element chemically bonded together. On the other hand, a molecule of a compound consists of two or more atoms of different elements chemically bonded together.
Hydrogen molecule is an example of molecule of an element. In it, two H atoms are bonded to give a molecule of hydrogen H2.
Example for molecule of a compound is nitric acid, in which one atom of hydrogen, one atom of nitrogen and three atoms of oxygen are chemically bonded together to form HNO3.
regards,
team Askiitians
