a. Smallest basic units of matter
[tex]\boxed{ \boxed{ \bf{ \bigstar \: Extra}}}[/tex]
Atom: An atom is the smallest particles of a substance which may or may not exist in free state but takes part in chemical reactions.
Molecule: A molecule is a substance which exists in free state but doesn't take part in chemical reactions.
Laws of chemical combination:-
- Law of conservation of mass
- Law of constant proportions
- Law of multiple proportions
- Law of reciprocal proportions
