The Periodic Table and the Atom - The Development of the Model of the Atom

Question 1

what may new scientific evidence lead to in regards to scientific models

Answer 1

the models being changed or replaced

Question 2

what were atoms thought to be before the discovery of the electron

Answer 2

tiny spheres that could not be divided

Question 3

what did the discovery of the electron lead to visa vi the model of the electron

Answer 3

the plum pudding model, which suggested that the atom is a ball of positive charge with negative electrons embedded in it

Question 4

what conclusion was drawn from the results of the alpha particle scattering experiment and how did this change the electron model

Answer 4

the mass of an atom was concentrated at the centre, the nucleus

This nuclear model replaced the plum pudding model

Question 5

Who adapted the nuclear model by suggesting what

Answer 5

Niels Bohr

the electrons orbit the nucleus at specific distances

Question 6

What idea was developed after the updated nucleus model and what was the name of the particles

Answer 6

the positive charge of any nucleus could be subdivided into a whole number of smaller particles each with the same amount of positive charge
These were called protons

Question 7

Who proved the existence of neutrons within the nucleus and when did he do it

Answer 7

James Chadwick

20 years after the nucleus became an accepted idea

Question 8

why did the scattering experiment lead to change in the atomic model

Answer 8

some alpha particles were being repelled by a tiny concentration of positive charge in the centre of the atom, e.g the nucleus