Bohr Diagrams

Bohr Diagrams Picture representation of an atom. Gives info about the nucleus, electrons, and energy levels.

Steps to drawing a Bohr Diagram: 1. Write symbol, # of protons and # of neutrons. # of protons Symbol 27-13 = # of neutrons

Steps to drawing a Bohr Diagram: 2. Add # of circles around this for # of energy levels needed (same as period #). Elements in the 1st period have one energy level. Elements in the 2nd period have two energy levels, and so on.

Steps to drawing a Bohr Diagram: 3. Add electrons to each orbital. Atomic # = # of protons = # of electrons Electrons are filled in as follows: 1st = 2 e- 2nd = 8 e- 3rd = 18 e-

Example: Aluminum

Example:

Example:

Electron Dot Diagrams

Electron Dot Diagrams Element's symbol surrounded by dots that represent the valence electrons.    An element will never have more than eight valence electrons.

Valence Electrons: The # of electrons in the outermost energy level. # of valence electrons stays the same up/down a group, but increase across the periodic table. They get most involved in chemical reactions.

How to determine the # of valence electrons?

Example: Silicon

Steps to drawing an Electron Dot Diagram: 1. Draw the symbol 2. Add dots around the symbol to represent the # of valence electrons. **These do not apply to transition metals.**

Example:

Example: