Topic 1- The Development Of The Model Of The Atom:

Question 1

What was the first development of the atom?

Answer 1

Atoms were thought to be tiny spheres that could not be divided

Question 2

What was the second discovery of the atom?

Answer 2

Discovery of electron -> Plume pudding model (atom is a ball of positive charge with negative electrons embedded in it.

Question 3

What was the third discovery of the atom?

Answer 3

Alpha particle scattering experiment -> conclusion that the mass of an atom was concentrated at the centre ( nucleus) and that the nucleus was charged.

Question 4

Describe the alpha scattering experiment.

Answer 4

A beam of alpha particles was aimed at a very thin gold foil and their passage through was detected.

Some of the alpha particles emerged from the foil at a 90° angle, some went straight through and some deflected straight back.

The positively charged alpha particles were being repelled and deflected by a small concentration of positive charge in the atom (nucleus)

Question 5

What was the fourth development of the atom?

Answer 5

Neil Bohr suggested that electrons orbit the nuclear specific distances.

Question 6

What was the fifth development of the model of the atom?

Answer 6

Bohr suggested positive charge of any nucleus could be subdivided into a whole number of smaller particles, each particle having the same amount of particle charge (protons).

Question 7

What is the current model of the atom?

Answer 7

James Chadwick provided the evidence to show the existence of neutrons within the nucleus.