Covalent Bonding●Covalent bond – Bonds between two nonmetals. Electrons are shared, rather than transferred.

●Electronegativities are not strong enough to pull electrons away completely, therefore, a covalent bond is formed from sharing electrons

•Molecules – chemical compounds made from covalent bonds • Molecules tend to be soft or brittle• Low melting points• Poor conductors of heat & electricity

Example: Chlorine atoms bonding to form Cl2Cl + Cl → Cl2

Lewis-Dot diagrams for covalent bonds are different than ionic bondsA dash is used to represent a pair of “shared” electrons

Types of Covalent BondingSingle Covalent Bond – One pair of electrons are shared between two nonmetals.

– Ex: Hydrogen bonding with Hydrogen

Double Covalent Bond – Two pairs of electrons are shared between two nonmetals.

– Ex: Oxygen bonding with Oxygen

Types of Covalent BondingTriple Covalent Bond – three pairs of electrons are shared between two nonmetals.

– Ex: Nitrogen bonding with Nitrogen

Quick Tips For BondingGroup 17 Halogens and Hydrogen only form one covalent bond

- one pair of electrons is shared to make a complete octet

Group 15 Nonmetals form three covalent bonds

- one triple bond, or a combination of double and single bonds.

Carbon can form up to four covalent bonds.

- any combination of single, double, or triple bonds

Group 16 Nonmetals form two covalent bonds• A double bond with another non-metal• 2 single covalent bonds

Bond PolarityNonpolar Covalent Bond – The bond created from an equal sharing of electrons.Atoms of the same element have the same electronegativity and produce nonpolar bondsEx. Br2, I2, N2, Cl2, H2, O2, F2Look familiar?

Polar Covalent Bond – Electrons are not shared equally.

- Between two different nonmetals, one will have a higher electronegativity

- the higher electronegativity produces a partial negative charge

- the lower electronegativity has a partial positive charge

- δ-- and δ+ are used to show a partial negative and partial positive charge

ElectronegativityHydrogen: 2.2Fluorine: 4.0