Lewis Structures and Chemical Bonding

Valence Electrons The electrons that exist in the outermost electron shell of an atom We can determine the number of valence electrons by drawing out electron configuration diagrams OR by looking at periodic table groups

Because Oxygen is in group 6, it has 6 valence electrons

Lewis Dot Structures Lewis Dot Structures are diagrams that show how many valence electrons an atom of an element has These structures also help show bonding between elements

To draw a lewis dot structure, you need to first know how many valence electrons an atom has Nitrogen has 5 valence electrons so you will have 5 dots in your diagram

How to Draw the Lewis Dot Structure for Cl

Determine the Element’s Atomic Symbol

Determine how many valence electrons Cl has

Start by drawing one dot at the top and move around the symbol counter clockwise until you’ve used up all of your available valence electrons

Chemical Bonding

What is Chemical Bonding? The attraction between atoms that allows for the formation of chemical substances that contain two or more atoms

Covalent Bonding Bond in which one or more pairs of electrons are shared by two atoms

Water (H2O) Carbon Dioxide (CO2)

How We Determine Covalent Bonds Atoms are “happiest” when they have 8 valence electrons If an atom has less than 8 valence electrons, it will try and bond with atoms that fulfill those 8 valence electrons

Oxygen has 6 valence electrons, so it needs to find 2 more valence electrons to complete its outer shell Hydrogen happens to have 1 valence electron Oxygen bonds with 2 hydrogen atoms to complete its outer shell to form H2O (water)

The lines between H and O represent the sharing of an electron

Ionic Bonding Bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract one another