Adapted from

www.middleschoolscience.com 2008

How to Draw Dot Diagrams or Lewis Structures

Review - Discussion

•How do you determine the information needed to draw the Bohr diagram of an atom?

Needed Information

• Valence electrons are the outermost electrons.

• How do you find the number of valence electrons?–The last number of the group number–Ex. Group 1 = 1, Group 18 = 8

• The highest number of valence electrons = 8. This is your magic number except for H and He!

• Maximum of 2 electrons per side.

Ne

Dot Diagrams or Lewis Structures• Find out which group

your element is in.• This will tell you the

number of valence electrons your element has.

• You will only draw the valence electrons.

www.chem4kids.com

Groups - Review

•Each column is called a “group”

•Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.

Except for He, it has 2 electrons

•The electrons in the outer shell are called “valence electrons”www.chem4kids.com

Lewis Structures1) Write the element

symbol.2) Carbon is in the 4th

group, so it has 4 valence electrons.

3) Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol.

4) Check your work!

Lewis Structures

Try these elements:a) Hb) Pc) Cad) Are) Clf) Al

Lewis Structures

Try these elements:a) Hb) Pc) Cad) Are) Clf) Al

Lewis Structures

Try these elements:a) Hb) Pc) Cad) Are) Clf) Al

Lewis Structures

Try these elements:a) Hb) Pc) Cad) Are) Clf) Al

Lewis Structures

Try these elements:a) Hb) Pc) Cad) Are) Clf) Al

Where are you on the scale?• 1: I can find the information but cannot

make the diagrams.• 2: I can make the diagrams most of the

time.• 3: I can consistently create the

diagrams.• 4: I can show others how to make the

diagrams and am ready to start combining dot diagrams.

Lewis Structures

Try these elements:a) Hb) Pc) Cad) Are) Clf) Al

Lewis Structures

Try these elements:a) Hb) Pc) Cad) Are) Clf) Al

Discussion

• Compare and contrast Bohr diagrams to Dot diagrams.