Farmers' Almanac TV: The Northern Lights

The Aurora Borealis, or Northern Lights, shines above Bear Lake, Eielson Air Force Base, Alaska

United States Air Force photo by Senior Airman Joshua Strang

Bohr's Conclusions

Think of an atom as a
miniature solar system

3 orbits are permitted
for this atom

1. Permitted orbits of an electron in an atom are limited

2. Each orbit is a different energy

3. Inside orbits have lower energies than the outside ones

4. When electrons in an atom change energy states they absorb or release energy

• Up energy level,
energy absorbed

• Down energy level,
energy released as light

Permitted Orbital Energies
for Hydrogen

Reference table

Each orbital is associated with a specific energy

Energy Level #	Energy
n = 3	-1.51 eV	Excited State
n = 2	-3.40 eV	Excited State
n = 1	-13.6 eV	Ground State Lowest Energy Level

Electrons can only absorb or emit energy that is equal to the difference between the absolute value of 2 energy levels.

A single photon of energy is given off when electrons go down energy levels.

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