Lewis Electron Dot Diagrams

• A diagram that shows outer (valence) electrons around a symbol of the element.

e.g.     C

• Why: the only electrons involved in chemical reactions are the outer energy level electrons; these are called the valence electrons.

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Steps to drawing a Dot Diagram:

1. Write the symbol of the element.

2. Write out the electron configuration for that element and underline the orbitals from the highest n level (they will be from s and p sublevels only)

e.g Carbon:            1s²2s²2p² Osmium: …6s²4f¹⁴5d⁶

Xenon: …  5s²4d¹⁰5p⁶

3. Each of the sides of the element symbol represents an s or p orbital. Draw in the electron dots for each orbital underlined in the electron configuration. Use 1 dot if only 1 electron in the orbital. Use 2 dots if 2 electrons are in the orbital.

example

selenium 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁴