QUANTUM CHEMISTRY

QUANTUM CHEMISTRY

Quantum chemistry is a branch of chemistry whose primary focus is the application of quantum mechanics in physical models and experiments of chemical systems. It is also called molecular quantum mechanics,Wikipedia.

But let’s break it down a little bit.

The first word is quantum

Quantum is the Latin word for amount. This could mean amount of energy or amount of a substance or a given measurable quantity in the field of science.

Take for instance when we say a dozen- it means 12, a score means 20.

The next word is mechanics

Mechanics is the science of a body’s movement when they have been subject to a of force. In this case the it is the part of science that studies of electrons surrounding the nucleus of the atom.

Quantum chemistry looks at electron's position in orbits, and how it relates to their corresponding energy levels within the parent atom.

           

Simple atom                                                Not- so simple atom.

The simple idea of electron model was developed by Rutherford in 1911.Based on his studies he discovered that atomic model is similar to the model of solar system such the earth was revolving round the sun within a confined circular space called orbit. The electrons were thought of as in stationary constant path from the nucleus of the atom.This was the simple atomic model as proposed by Rutherford.

A NEW OBSERVATION: BOHR'S MODEL

Neil Bohr showed that when hydrogen absorbs energy in the form of light or heat,it electrons tends to be excited with energy. With an atomic number 1, which also means it has a single electron. Under normal conditions hydrogen single electron is at ground state which is the initial level of the atom when at rest.The initial ground state is the minimum energy level that the electron possess when the atom is not influence by any external source of energy.

(a)electron returning to the ground state  (b)emission of light spectra from electron losing energy.

As the electron absorbs energy it takes up this extra energy to move faster then when a certain amount of energy is achieved, it jumps to a higher orbit of higher energy level. This behaviour is repeated as long as there is energy supply.

When the source of energy is removed,the electron returns back after excitement,it jumps back step by step down the energy level it behaviour leaves  trail of light ascalled line spectra when the electron was returning to it initial position of rest know as ground state.