Programme 17: Atomic Structure

Programme Questions: Activity Sheet 1

Atomic Structure

1. What was J J Thompson studying when he discovered electrons?
2. If cathode rays are deflected by a very small magnetic field, does this suggest they are heavy or light?
3. If the strength of the electric field in Thompson’s experiment were increased what would happen to the amount the rays are deflected?
4. Why did Rutherford carry out his gold foil experiment in a vacuum?
5. What is the charge and relative mass on each of these particles?

	Electron	Proton	Neutron
Charge
Mass

Atomic Number and Mass Number

1. Which element has the lowest atomic number?
2. Does atomic number increase in a regular way?
3. What is the atomic number of an atom equal to?
4. Which is bigger, the atomic number or the mass number?
5. What is an atom’s mass number equal to?

Electron Structure

1. Where are the electrons found in an atom?
2. What is the maximum number of electrons that can fit into the first shell?
3. What is the maximum number of electrons that can fit in the second and third shells?
4. What is the electron arrangement in an atom of magnesium and which group of the periodic table does it belong to?