Covalent Bonding

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

Hydrogen(H) Hydrogen is a gas. Hydrogen has only 1 electron in its outer shell 1P 0N Hydrogen H= 1,1

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

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. Watch how! 1P 0 N 17P 18N H Cl

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

HCl 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. 1P 0N 17P 18N H Cl

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.

To satisfy the Octet Rule, atoms tend to gain, lose or share electrons H and Cl shared one pair of 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. 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.

Other examples of Covalent Bonds 2 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. 1P 0N 1P 0N H H

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

X O B. Lewis Structures 2s 2p Electron Dot Diagrams show valence e- as dots distribute dots like arrows in an orbital diagram 4 sides = 1 s-orbital, 3 p-orbitals EX: oxygen X 2s 2p O

Ne B. Lewis Structures Octet Rule Most atoms form bonds in order to obtain 8 valence e- Full energy level stability ~ Noble Gases Ne

B. Lewis Structures - + Nonpolar Covalent - no charges Polar Covalent - partial charges + -

C. Molecular Nomenclature The Seven Diatomic Elements Br2 I2 N2 Cl2 H2 O2 F2 H N O F Cl Br I