1. Quantum Mechanics Theory
Quantum means packet or bundle
Quanta are discrete steps

2. Quantum replaces classical
Classical (Newtonian) Mechanics is still valid at speeds, sizes and distances which you encounter on a daily basis.
Miles
55 mph
Loaf of bread
On the atomic level, classical mechanics fails

3. Quanta and the Spectrum
We use the visible light spectra from stars to determine all the information we have about them
The vertical lines of light we see on an emission spectra are produced when an electron falls to a lower energy level and a photon is released.

4. Quanta and the Spectrum
The electron goes to a higher energy shell (makes a quantum leap) when it is struck by a photon of just the right energy.