Covalent Bonding

Illustration of the formation of the Covalent bond between Hydrogen and Chlorine HCl

Hydrogen(H) 11P 12N Hydrogen H= 2,1 Hydrogen is a gas. Hydrogen has only 1 electron in its outer shell

Chlorine (Cl) 18P 17N Chlorine = 2,8,7 Chlorine is a poisonous gas. It has 7 electrons in the outside shell and is not stable.

Neither Hydrogen nor Chlorine are stable, since both have less than 8 electrons in their outside shell. However this can easily be achieved by combining H and Cl together. 17P 18N 1P 0 N HCl Watch how!

A covalent bond will be formed between H and Cl by sharing a pair of electrons …. 17P 18N 1P 0N H Cl A Hydrogen atom has only 1 electron which it cannot lose. Therefore, the only type of bond H can form is a covalent bond

HCl 17P 18N 1P 0N H Cl 1 atom of Hydrogen has combined with 1 atom of Chlorine. Both H and Cl are now in a stable state - each with a full outer shell.

Satisfying the Octet Rule….. The Octet rule is simply a rule which helps us to understand bonding Atoms bond together so that each atom attains an electron arrangement of 8 electrons in its outermost shell. The Octet Rule :

To satisfy the Octet Rule, atoms tend to gain, lose or share electrons The H began with 1 electron in its outer shell - It needed 2. The Cl atom began with 7 electrons in its outer shell - It needed 8. H and Cl shared one pair of electrons By sharing the pair of electrons, both atoms are now in a stable state. H has 2 electrons in its outer shell and Cl has 8 in its outer shell.

H 1P 0N 1P 0N H H 1 atom of Hydrogen has combined with 1 atom of Hydrogen. Both Hydrogens are now in a stable state - each with a full outer shell. 2 Other examples of Covalent Bonds

The Water molecule 1P 0N 8P 8N O H H 2 1P 0N O H

Both Na and Cl now have 8 electrons in their outside shell and a new compound NaCl has been formed 17P 18N 11P 12N Na+ 2,8 Cl- 2,8,8

Both Na and Cl now have 8 electrons in their outside shell and a new compound NaCl has been formed 17P 18N 11P 12N Na+ 2,8 Cl- 2,8,8 Strong forces of attraction exist between Na+ and Cl- and hold the bond together