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: -There are 3 basic particles that make up an atom: protons, neutrons, and electrons. The center of the atom, or the nucleus, contains both protons and the neutrons. Surrounding the nucleus is the electron cloud, where the electrons are existing in the outermost regions of the atom in electron shells.