1. Electron Cloud Structure

2. Electron cloud structure In a neutral atom the # of electrons will equal the # of protons

3. Energy levels Energy levels nearer to the nucleus have lower energy than those levels that are farther away. Elements in same group have the same number of electrons in the outer levels.

4. Energy levels Energy levels in atoms can be represented by a flight of stairs. Each stair step away from the nucleus represents an increase in the amount of energy within the electrons. The higher energy levels contain more electrons.

5. Different Energy Levels Floor (nucleus) – Step 1 = energy level 1  2 electrons – Step 2 = energy level 2  8 electrons – Step 3 = energy level 3  18 electrons – Step 4 = energy level 4  32 electrons

6. Electron dot diagram Uses the symbol of the element and dots to represent the electrons in the outer energy level.

7. Bohr Model Based on number of protons, neutrons and electrons. Place the # of protons and neutrons in the first ring of the circle. Place the electrons starting in the closest ring to the center and filling them up as the levels are filled outwards Levels… – 1 st = 2 – 2 nd = 8 – 3 rd = 18

8. Lewis Dot structure Symbol of element Number of electrons in the outer shell