An atom is the elementary building piece of a physical matter. An atom cannot be broken down further through a chemical means. When combined together, atoms make molecules that form majority of physical objects around us. Atoms comprise particles known as neutrons, electrons and protons. Protons contain positive charge while electrons contain negative charge. There is neither positive nor negative charge in neutrons. Neutrons and protons collect together at the core of an atom. The center-most part of an atom is known as the nucleus. Electrons rotate around an atom’s nucleus.  The number of electrons in any atom is equal to the number of protons.  The number of neutrons in most atoms is also equal to the number of protons. Atoms are of different kinds, 90 of existing atoms occurred naturally while scientists developed 25 more in the laboratories.

Composition of Neutrons and Protons

Neutrons and protons contain additional particles known as gluons and quarks. Gluons bind the quarks to each other. There are two types of quarks, the ‘up’ quarks’ and the ‘down’ quarks. Protons are made up of 1 ‘down’ quark and 2 ‘up’ quarks. If a sentence has only one type of atoms, it is referred to as an element. For instance, a hydrogen element comprises atoms with one proton and one electron. If the quantity of protons in an atom is changes, then the element changes too.

Difference between a Molecule and Compound

Molecules are formed when 2 or more atoms combine chemically. When two distinct elements combine, they form a compound. Though each compound is a molecule, all molecules are not necessarily compounds. For instance, hydrogen, oxygen and nitrogen contain single elements each and therefore are not compounds. Carbon dioxide, methane and water contain more than 1 element and are therefore compounds.