Question: Why do physics change so drastically at a subatomic level?

Josh Meyers answered on 15 Jun 2015:

This is called the quantum level and it doesn’t really change at all! There are specific energy levels that are ‘allowed’ for any particle.

The gaps between these energy levels are only significant for the smallest of particles. We can ignore them for normal ‘classical’ mechanics but when it comes to subatomic particles we have to start considering quantum mechanics.