What is Quantum Mechanics?

Quantum Mechanics is the science of the small. If we are to consider the interactions between the molecules, atoms and the sub-atomic particles, we need to follow the quantum mechanical procedures. Thus, in a sense, quantum mechanics is a tool to study the behavior of the atomic and subatomic particles. The fundamental equation of Quantum Mechanics is the Schrodinger equation, which is like Newton's second law of motion in Classical Mechanics. We treat matter as a wave or a wave packet and a wave function, commonly denoted by 'psi' is assigned to the matter wave. Under different initial and boundary conditions as specified in the problem, the Schrodinger equation is solved to get the wave function for that particular problem. The more meaningful quantity is the modulus square of the 'psi' function - which gives the probability of finding the particle at any place. There is nothing certain in quantum mechanics, all is what is probabilistic. The probability of finding a particle is high where the square of the 'psi' function is high. The integral of the square of the 'psi' function in overall space is 'one', meaning that the particle must be situated somewhere in the space defined in the problem.