1. Bohr Diagrams Electron Energy States

2. Bohr Model Bohr - electrons in an atom can have only specific amounts of energy NEW idea! quantum number (n) assigned to each orbit –the smallest orbit (n= 1) is closest to the nucleus has the lowest energy the larger the orbit, the more energy it has –n = 7 has highest energy

4. Bohr Diagram Shows all the electrons in orbits or shells about the nucleus. n=1 n=2 n=3 E1E1 E2E2 E 3 n=1 n=2 n=3

5. Electron Transitions Energy is absorbed: –electron gains energy, becomes excited and moves to higher orbit (farther from nucleus) – Endothermic process Energy is released: –electron loses energy and drops to lower orbit (closer to nucleus) – Exothermic process –LIGHT is emitted

6. energy levels get closer together as move away from nucleus Larger orbits hold more electrons

7. Max Capacity of Bohr Orbits 2n 2 n 324 183 82 21 Max # of ElectronsOrbit

8. Ground State vs. Excited State Ground state: –lowest energy state of atom –electrons are in lowest possible energy levels Configurations in Reference Tables are ground state Excited state: –many possible excited states for each atom –one or more electrons excited to higher energy level

9. 2-8-5 ground state excited state possibilities: 2-8-4-1 2-8-3-2 2-8-3-1-1 etc