GENERAL KNOWLEDGE

Detailed explanation-1: -Scientists once thought the most fundamental building block of matter was a particle called the atom. Now we know that the atom is made of many smaller pieces, known as subatomic particles. Every atom contains a central core called the nucleus, made of particles called protons and neutrons.

Detailed explanation-2: -Atoms are the building blocks of matter.

Detailed explanation-3: -John Dalton formulated the law of multiple proportions as part of his theory that atoms formed the basic indivisible building block of matter.