In 1922, Neils Bohr won the Nobel prize in physics for his understanding of atomic structure. His theory states that electrons have fixed amounts of energy and travel in circular orbits around the atom’s nucleus.

Rules to Draw Bohr Diagrams 1. Draw the nucleus and state the number of protons and neutrons in it. 2. Draw the number of orbits needed (= the period that the element is in) 3. Fill in electrons. The maximum amount of electrons found in the: First orbit = 2 2nd orbit = 8 3rd orbit = 8 4th & 5th orbit = 16 6th and 7th = 32

Example: Drawing Magnesium:

How Atoms Become Stable Let’s draw the Bohr Diagram of the first 3 Noble Gases:

What do you notice about valence (outer) shell of all the noble gases? They are at capacity! They are full! They are complete 

Which is easier for Li to become stable? What about metals? Lithium: *metals will lose electrons to become positively charged Which is easier for Li to become stable? a) Lose 1 electron b) Gain 7 electrons?

Therefore, it has an extra positive charge! If Lithium loses it’s 1 valence electron, it will no longer be a “neutral” atom. It has: 3 protons 2 electrons Therefore, it has an extra positive charge! Draw out the representation!

Which is easier for S to become stable? Ex: Draw the Bohr diagram for the non-metal, sulfur * non-metals will gain electrons to be negatively charged Which is easier for S to become stable? a) Lose 6 electrons b) Gain 2 electrons?

Sulfur now has 16 protons and 18 electrons. We would write this as…