BOHR'S MODEL

THE BOHR's ATOMIC model DIAGRAM

Objective:

Identify and use previous knowledge to arrange electrons in orbitals using Borh's model.

ATL's skills:

Combine knowledge, understanding and skills to create products or solutions

Transfer skills:

How are electrons placed?

• The first shell (orbit) can hold up to 2 electrons

• The second can hold up to 8 electrons

• The third shell can hold up to 18 electrons (usually only contains 8 electrons)

• The fourth, fifth, sixth and seventh shell can hold up to 32 electrons

Bohr's Model

• Complete model
• Compact model

Bohr's Model

Complete and compact model

Steps to draw the Bohr's diagram

1. Find the element on the periodic table. 2. Determine the number of electrons (atomic number). 3. These are the electrons you will draw.

Steps to draw the Bohr's diagram

4. Determine the electron configuration according to the diagram. z=6 1s 2s 2p

2 2 2

Example: Carbon:

Steps to draw the Bohr's diagram

P = 6 N = 6

5. Calculate the number of Protons and Neutrons 6. Write the number of protons and neutrons the element has inside the nucleus (P and N ).

+ +/-

+ +/-

Steps to draw the Bohr's diagram

7. Draw the number of shells or orbitals according to the electron configuration

C P = 6 N = 6

Steps to draw the Bohr's diagram

8. Write down the number of electrons in each shell.

1º shell= 2 electrons 2º shell= 4 electrons

C P = 6 N = 6

Complete

Compact

C- 2 . 4

Remember: Valence electron

Valence electrons

Is an outer shell electron that can participate in the formation of a chemical bonds.

What are the valence electrons for Carbon?

C P = 6 N = 6

2 4

Ex.1 Let's draw the Bohr's diagram for Chlorine

Ex.1 Solution: Bohr's diagram for Chlorine

1º shell= 2 electrons 2º shell= 8 electrons 3º shell= 7 electrons

Cl P = 17 N = 18

2 8 7

Ex.1 What are the valence electrons for Chlorine?

Cl P = 17 N = 18

2 8 7

Ex.2 Let's draw the Bohr's diagram for Iron

Ex.2 Solution. Bohr's diagram for Iron

1º shell= 2 electrons 2º shell= 8 electrons 3º shell= 14 electrons 4º shell= 2 electrons

Fe P = 26 N = 30

+ +/-

2 8 14 2

In your notebook: Thinking routine 3-2-1

-Write down 3 new things you have learned. -Mention 2 characteristics of the Bohr's model. -Explain how did you use previous knowledge to arrange electrons using the Bohr's Model.