Introduction to Bonding

Role of Valence Electrons Valence (Outer Shell) electrons are the only electrons that are involved in bonding. This happens based on an atom’s tendency towards a full outer shell. There is stability in having a full outer shell.

Full Octet Atoms want to have a full outer shell of electrons. Usually this is eight. This is why noble gases are unreactive. To get a full octet, most atoms need to either gain, lose, or share electrons. This is determined by the number of valence electrons they have.

Electronegativity The strength of hold an atom has on it’s valence electrons. If it is high, it will keep it’s valence electrons and gain more. If it is low, it will lose it’s valence electrons.

Types of Bonding Ionic Electrons are transferred from one element to the other. Happens between a non- metal and a metal. Metals form the Cation (+) and non-metals form the anion (-). Happens when the electronegativity difference is greater than 1.6.

Types of Bonding Covalent Electrons are shared between the elements involved. Happens between non- metals. Hydrogen acts as a non- metal for this.

Types of Bonding Non-polar covalent Polar covalent Electrons are equally shared. Happens when electronegativity difference is less than 0.5. Polar covalent Electrons are unequally shared with the more electronegative element being partial negative, and the lesser being partial positive. Happens when electronegativity difference is 0.5-1.6.

Types of Bonding Metallic Electrons are shared between the elements in a sea of electrons. Happens between metals. Electrons flowing freely is what allows metals to bend.