1. Bohr-Rutherford Diagram

2. The Bohr Diagram
Bohr suggested that there was a pattern to the position of electrons.
He believed that electrons moved around different orbits around the nucleus, just like planets do around the Sun

3. How to draw a Bohr-Rutherford Diagram
The electrons can move up and down the orbits but must stay on an orbit.
The nucleus is represented by a circle with P and N, the electrons are outside in energy levels
The pattern of electrons in the energy levels is
2, 8, 8, 2 for the first 20 elements
Li 2)1e-
P 2)8 )5e-
Ca 2)8 )8 )2e-

4. How to draw a Bohr-Rutherford Diagram
Draw a circle to represent the nucleus of the atom
Write the number of protons and neutrons inside the circle
The electrons are shown by using circles on the orbits around the nucleus
Once you have drawn the maximum amount of electrons that are allowed on the orbit you can start a new energy (orbit) level .Atoms are stable when their shell is full.

5. The amount of protons and electrons in each atom is the same as the atomic number!
To calculate the number of neutrons in an atom you must subtract the atomic mass from the atomic number

7. The electrons in the last shell are called valence electrons.
Valence electrons are involved in bonding.
Atoms will gain or lose electrons to make their outer shell full, the atom becomes charged and is called an ion.
Cation = atom that loses an electron and becomes positively charged
Anion = atom that gains an electron and becomes negatively charged.

8. Elements (#21 +) 1st level hold up to 2 e’s
2nd level holds up to 8 e’s
3rd level holds up to 18 e’s (but before placing more than 8e’s in this level you have to place 2 e’s in the 4th level before you can go back to fill in the 3rd level)
4th level holds up to 32 e’s (but before placing more than 8e’s in this level you have to place 2 e’s in the 5th level before you can go back to fill in the 4rd level
Rb e-
Br e-