User:JeevajivaS

ATOMS
The atom is a basic unit of matter consisting of a dense, central nucleus surrounded by a cloud of negatively charged electrons. An atom is the smallest unit of an element that could part in a chemical reaction. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons. The electrons of an om are bound to the nucleus by the electromagnetic force. Likewise, a group of atoms can remain bound to each other, forming a molecule.

An atom is classified according to the number of protons and neutrons in its nucleus: the number of protons determines the chemical element, and the number of neutrons determine the isotope of the element. Atoms, in turn, are made up of electrons, protons and neutrons in various combinations.

Electrons
Electrons are tiny, subatomic particles that are 'negatively' charged. Their mass is insignificant compared to that of protons and neutrons.

Protons
Protons are small, subatomic particles that are 'positively' charged. Their mass is not ignored in calculations of atomic mass, but is given a value of 1 amu. The atomic number of an element is the number of atoms in one atom of an element.

Neutrons
A neutron is a particle that has no charge.

Ions
An ion is an atom possessing an electric charge. Atom which contain more electrons than protons are said to be negatively charged ions or anions, while atoms possessing more protons that electrons are said to be positively charged ions or cations. Sometimes, group of atoms possessing an electric charge which react as a single unit is called a radical.