Intro to Bonding: Part 2: Covalent Compounds (Type 3 Binary Compounds)

Types of bonds There are 3 types of bonds that we are going to focus on: 1.Ionic Bonds 2.Covalent Bonds Polar Nonpolar 3.Metallic Bonds

Covalent Bonds A bonding force resulting from the sharing of valence electrons. Covalent compounds result when a nonmetal reacts with another nonmetal. This type of bond is not as strong as an ionic bond.

Covalent Bonds Example: – Water (H 2 O) There is no cation or anion Both Hydrogen & Oxygen are nonmetals Hydrogen has 1 valence electron – Hydrogen needs 2 valence electrons to fill it’s outermost energy level – Oxygen will share one of it’s electrons so that Hydrogen can fulfill the duet rule (2 electrons in the outermost energy level). Oxygen has 6 valence electron – Oxygen needs 8 valence electrons to fill it’s outermost energy level – Each hydrogen will share it’s one electron so that oxygen can fulfill the octet rule (8 electrons in the outermost energy level). If both hydrogen’s share their 1 valence electron with oxygen, then each hydrogen will have a total of 2 valence electrons (duet rule) and oxygen will have a total of 8 valence electrons (octet rule).

Single, Double, Triple Bonds By drawing the Lewis dot structure, you can determine if there is a single, double, or triple bond between atoms. Single bond – Each atom shares one valence electron Double bond – Each atom shares two valence electrons Triple bond – Each atom shares three valence electrons.

Single, Double, Triple Bonds Bonds are represented by solid lines:

Nonpolar Covalent Bonds A nonpolar covalent bond is when electrons are shared equally. An example is Oxygen gas (O 2 ): – Each oxygen atom has 6 valence electrons – Each oxygen is going to share 2 valence electrons. – Oxygen is left with 2 lone pairs on each oxygen atom. Thus there is an equal distribution of electrons. – Oxygen gas would be a nonpolar covalent compound.

Polar Covalent Bonds A polar covalent bond is when electrons are shared unequally. An example is Water (H 2 O): – Each hydrogen has 1 valence electron. – Oxygen has 6 valence electrons. – Each hydrogen will share it’s one electron so that oxygen can fulfill the octet rule. – Oxygen will share one of it’s electrons so that Hydrogen can fulfill the duet rule. – Hydrogen is left without any lone pairs. Oxygen has 2 lone pairs. Thus there is an unequal distribution of electrons. – Water would be a polar covalent compound.