Valence Electrons and Lewis Dot Diagrams Ms. Khericha and Ms. Rowland

Electron Cloud Electron Cloud

Energy Levels

Valence electrons Valence electrons are the electrons farthest away from the nucleus. Every group of elements will have a different number of valence electrons

Why are valence electrons important? Valence electrons are key to whether or not an atom bonds with another atom The number of valence electrons is the “face” an atom shows to other atoms One way to show valence electrons is with electron dot diagrams or Lewis dot diagrams

Lewis dot diagrams Lewis dot diagrams include the symbol for the element surrounded by dots. Each dot stands for one valence electron Hydrogen Hydrogen H Nucleus

How to find the # of valence electrons Find out which group (column) your element is in. This will tell you the number of valence electrons your element has. You will only draw the valence electrons.

Groups Elements in group 1 will have only 1 valence electron Group 1 = 1 electron

Groups Elements in group 2 will have only 2 valence electron Group 2 = 2 electrons

Groups Elements in group 3 will have only 3 valence electron Group 3 = 3 electrons

Groups Elements in group 4 will have only 4 valence electron Group 4 = 4 electrons

Groups Elements in group 5 will have only 5 valence electron Group 5 = 5 electrons

Groups Elements in group 6 will have only 6 valence electron Group 6= 6 electrons

Groups Elements in group 7 will have only 7 valence electron Group 7 = 7 electrons

Groups Elements in group 8 will have only 8 valence electron Group 8 = 8 electrons Except for He, it has 2 electrons

Groups - Review Group 8 = 8 electrons Group 1 = 1 electron Except for He, it has 2 electrons Group 2 = 2 electrons 3, 4, 5, 6, 7

How to: Lewis Structures Find your element on the periodic table. Determine the number of valence electrons. This is how many electrons you will draw. Draw them starting at the right, and in a counterclockwise manner.

Lewis Structures Write the element symbol. C

C Lewis Structures Write the element symbol. Carbon is in the 4th group, so it has 4 valence electrons. C

C Lewis Structures Write the element symbol. Carbon is in the 4th group, so it has 4 valence electrons. Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol. C

Practice!

Lewis Structures H

Lewis Structures H

Lewis Structures P

Lewis Structures P

Lewis Structures Ca

Lewis Structures Ca

Lewis Structures Ar

Lewis Structures Ar

Lewis Structures Cl

Lewis Structures Cl

Lewis Structures Al

Lewis Structures Al

Assignment You will have the rest of the hour and the weekend to complete the Lewis structures assignment