Question

Describe at least two changes that occurred to the atomic model over time, along with the experimental evidence that made these changes necessary.

Help pleasee

Answer 1

There is a long story of atom. Many scientist gave different theories related to atom. Some of famous atomic modal are as follows

Thomson Atomic Modal

in 1904 J. J. Thomson proposed an atomic modal which is known as plum pudding modal. According to Thomson The shape of an atom is spherical in which positively charged matter is filled and electrons are randomly scattered in that positively charged matter.

Experimental evidence

J.J. Thomson's experiments with cathode ray tubes showed that each atom has negatively charged particles which is known as electrons.

Rutherford atomic modal

in 1911, Rutherford gave new atomic modal. He proposed the concept of nucleus. According to Rutherford atomic modal at the center of atoms all positively charged particles are present and this center is known as nucleus. He said that negatively charge electrons revolves around the nucleus in particular orbit.

Experimental evidence:

In rutheford modal, Rutherford shooted alpha particles on very thin gold foil. He observed that some of the alpha particles get deflected by gold foil. which proved proved that an atom has a nucleus which is surrounded by electrons.

Answer 2

I think you could use Bohr model and the Plum Pudding Model

Bohr Model : the one that states atoms consist of positively charged nucleus and orbited by negatively charged electrons

Plum Pudding model : Atom consist of objects made to pieces with positive and negative charges

hope this helps