Answers to GCSE Atomic Structure

Practice Questions

1. State the names of the three subatomic particles present in and atom.

Protons, Neutrons and Electrons

2. The radius of a typical atom is 1 x 10^-10m. Calculate the size of the radius of the nucleus.

The nucleus is 1/10000th the size of the atom.

1 x 10^-10/10000 = 1 x 10^-14m

3. Calculate the relative mass of the nucleus that is seen in the picture of the atom at the very top of this page.

There are 3 protons and 4 neutrons. Both protons and neutrons have a relative mass of 1. So, therefore total relative mass is 7.

4.State how many electrons as a maximum should be in the first, second and third energy levels of an atom.

First energy level holds up to two electrons, second or third energy level holds up to 8 electrons