Question

How did the atom model change over time?

Answer 1

Hint: The atomic structure of an atom was first given by John Dalton and was then modified by a number of scientists where new assumptions were given for the atom. Lastly Rutherford's model was proposed by a gold foil experiment.

Complete step by step answer:
The structure of an atom contains a center called a nucleus which contains protons and neutrons. The electrons revolve around the nucleus in a circular orbit with fixed energy and velocity. There are so many assumptions related to the structure of atoms which are changed with the time.
The first theory of atomic structure was proposed by John Dalton in 1800. The Dalton atomic theory says that the atom is the smallest fundamental particle which cannot be further subdivided. The atoms of different elements are different.
As Dalton atomic theory had some drawbacks. The atomic model was then modified by J.J Thomson. The J.J Thomson says that the atom is made up of positive charge and the electrons are embedded like plum pudding.
After the J.J Thomson model, Bohr’s atomic model is proposed. He said that an atom has the center called a nucleus where electrons revolve around the nucleus. During the revolution the electrostatic force is generated between the nucleus and electrons. During the revolution, electrons neither gain nor lose energy.
After the Bohr model, Rutherford model was proposed known as alpha scattering model. He discovered nucleus and discovered that electrons move in circular orbit. Some atoms are hollow. The number of protons is the same as the number of electrons.

Note:
The Rutherford model is also known as gold foil experiment. Rutherford was not able to explain the line spectrum.