Atom

The fundamental particle of the natural world is atom. Any matter is composed of a few building blocks called as atoms. An atom is a Greek word which means “not divisible”.

Rutherford’s model

Rutherford had an idea that atom is a positive charge and the mass of the atom is distributed throughout the whole atom along with the electrons scattered out. This looks like a loosely packed snow ball. This idea was tested by passing the alpha particle beam in the piece of gold foil. The most of the alpha particle pass through the gold foil and the direction does not change. But some of the particle bounce back  in the opposite direction.

Hence Rutherford concluded that snow ball model of atom is incorrect and gave an idea that atom is a positive charge with dense mass at its core.

Niels bhor’s atom model

He modified the Rutherford’s atom model by setting the electrons with energy level which will not make the atom to collapse.