Quantum Physics

Why we need Quantum physics?
Quantum physics is the physics that explains things like motion of the incredibly small matter. This is different when compared to Newtonian physics, which describe motion,velocity, acceleration and energy transformations during collisions. But quantum physics describes how the electrons are surrounding the nucleus of the atom and many other subatomic actions.
Both explains how the matter is interacts with other matters but there is a big difference since general laws of physics will not be fully applicable when it comes to small scales. So we need quantum physics when we deal with small particles.

Quantum model of an Atom
The quantum model of the atom is very complex than the traditional model we have learned in school. This is definitely due to the fact that it needs very complex math to explain the behaviors and properties of small particles in the atom. It is even more difficult when it comes to subatomic particles. To find the exact position and velocity of an electron is very hard to find because that involves bouncing of other particles with it. These collisions changes the electron's velocity. The quantum physics find the location of the electron at any time using the statistical probability.