Adapted from www.middleschoolscience.com 2008 How to Draw Dot Diagrams or Lewis Structures Adapted from www.middleschoolscience.com 2008

Learning Scale 4 – Investigate and describe the compounds formed by bonding elements. 3 – Describe how elements combine to form compounds. Explain how groups of elements are similar to each other. 2 – Use the periodic table to identify the number of protons, neutrons, or electrons in an element. 1 – Locate and identify elements on the periodic table. 

Think Pair Share How do you determine the information needed to draw the Bohr diagram of an atom?

C Bohr Diagrams Draw a nucleus with the element symbol inside. Carbon is in the 2nd period, so it has two energy levels, or shells. Draw the shells around the nucleus. C

Bohr Diagrams Since you have 2 electrons already drawn, you need to add 4 more. These go in the 2nd shell. Add one at a time -starting on the right side and going counter clock-wise. C

C Bohr Diagrams Check your work. You should have 6 total electrons for Carbon. Only two electrons can fit in the 1st shell. The 2nd shell can hold up to 8 electrons. The 3rd shell can hold 18, but the elements in the first few periods only use 8 electrons. C

Let’s learn an easier method to determine who bonds with who Instead of this … All we need is this …

Information to Remember 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 electrons in the outer shell are called “valence electrons” Group 18 = 8 electrons Group 1 = 1 electron Except for He, it has 2 electrons Group 2 = 2 electrons Each column is called a “group” 3, 4, 5, 6, 7 Each element in a group has the same number of electrons in their outer orbital, also known as “shells”. The electrons in the outer shell are called “valence electrons” www.chem4kids.com

Dot Diagrams or Lewis Structures Find out which group your element is in. Look at the last number of the group number. This equals your valence electrons.

The highest number of valence electrons = 8 The highest number of valence electrons = 8. This is your magic number except for H and He! Maximum of 2 electrons per side.

C Lewis Structures Write the element symbol. Carbon is in the group 14, so it has 4 valence electrons. Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol. Check your work! C

Lewis Structures Try these elements: H P Ca Ar Cl Al C

Lewis Structures Try these elements: H P Ca Ar Cl Al H

Lewis Structures Try these elements: H P Ca Ar Cl Al P

Lewis Structures Try these elements: H P Ca Ar Cl Al Ca

Lewis Structures Try these elements: H P Ca Ar Cl Al Ar

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: H P Ca Ar Cl Al Cl

Lewis Structures Try these elements: H P Ca Ar Cl Al Al

Compare and contrast Bohr diagrams to Dot diagrams. Think Pair Share Compare and contrast Bohr diagrams to Dot diagrams.

Learning Scale 4 – Investigate and describe the compounds formed by bonding elements. 3 – Describe how elements combine to form compounds. Explain how groups of elements are similar to each other. 2 – Use the periodic table to identify the number of protons, neutrons, or electrons in an element. 1 – Locate and identify elements on the periodic table.