Chemical Bonding (Introduction)

consists of:


-Ionic Bonding
-Covalent Bonding
-Metallic Bonding

Atoms are made up of smaller particles known as Subatomic particles (Protons, Neutrons and Electrons).

Particle	Symbol	Relative Mass	Charge
Proton	p	1	1+
Neutron	n	1	0
Electron	e-	1/1836	1-

Proton number refers to the number of protons in an atom and it is also known as atomic number.

Nucleon number refers to the number of protons and neutrons in the nucleus of an atom and it is also called the Mass number.


Number of protons and neutrons -> Nucleon number/ Mass number.

The centre of an atom is called the nucleus which contains the protons and neutrons.

The electrons in an atom are arranged in shells at different distances from the nucleus. The shell nearest to the nucleus is numbered 1, the second nearest is numbered 2 and so on.

1st shell is the only shell that holds 2 neutrons with the following shells holding a maximum of 8 neutrons.

From the picture, the electronic configuration of Magnesium is 2.8.2.

When an atom loses one or more electrons, it becomes a positively charged particle called cation.

When an atom gains one or more electrons, it becomes a negatively charged particle called anion.

Charge of ion	Element	Name of ion	Symbol of ion	No. of electron gained	No. of electron lost
-2	Oxygen Sulfur	Oxide Sulfide	O2- S2-	2
-1	Fluorine Chlorine	Fluoride Chloride	F- Cl-	1
+1	Hydrogen Lithium Sodium Potassium	Hydrogen Lithium Sodium Potassium	H+ Li+ Na+ K+		1
+2	Beryllium Magnesium Calcium Copper Iron	Beryllium Magnesium Calcium Copper (II) Iron (II)	Be2+ Mg2+ Ca2+ Cu2+ Fe2+		2
+3	Aluminium Iron	Aluminium Iron (III)	Al3+ Fe3+		3