Atom
Atom - smallest particle of an element, which is consist of three sub-atomic particles - electron, proton and neutron.
Matter
Anything has mass and occupies space called matter. There are four states of matter - solid, liquid , gases and plasma.
Molecule
molecule is the smallest particle in a chemical element or Compound that has the chemical properties of that element or Compound. Molecules always formed by the sharing of electron or exchange of electron.
If we talk about the types of molecules - there are three types
Mono- molecule consist of single atom- Ar, K , Ca
Diatomic molecule consist of two atoms -
Polyatomic molecule- consist of more than two atoms -
Substance
Substance - Piece of matter in pure form which has fixed composition and properties for example tin, sulfur and diamond sodium chloride and baking soda.
Element
Substance made of same type of atoms having same atomic number. Elements can occur in free state or in combined form like solid, liquid and gases. up till now 118 elements has been discovered and most of them are solid. Elements are divided into metals, non- metals and metalloids.
