1. Quantum Theory & the Atom
Light is explained by the dual wave-particle model , but what are the relationships among atomic structure, electrons, and atomic emission spectrum??

3. The Bohr Model of the Atom
Neils Bohr suggested that only certain electron orbits are allowed.
Orbits are given numbers n=1,2,3,4,5,…,infinity.
n=1 is the ground state (ground orbit) and has the lowest energy. No lower orbit is permitted.
The excited states (higher orbits) have more energy.
The orbits get closer together as n increases.
To change orbits, the electron must either gain or loose energy.
Each type of atom has a unique set of energy levels.