1. Who proposed that all matter was composed of a combination of earth, air, fire and water?

a) Democritus
b) Dalton
c) J. J Thomson
d) Empedocles

2. What was a key limitation of Democritus' atomic theory?

a) It was based entirely on experimental evidence
b) It lacked any practical work or evidence
c) It was not widely accepted at the time
d) It correctly identified that atoms were solid particles that could not be split

3. Who first proposed the idea of atmos or atoms?

a) John Dalton
b) Issac Newton
c) Democritus
d) Plato

4. John Dalton's atomic theory correctly explained the law of mass; this law states that the total mass of the reactants in a chemical reaction is equal to the total mass of the .

5. Who is credited with the discovery of the electron?

a) J.J Thomson
b) John Dalton

6. What are cathode rays?

a) Positively charged particles
b) Negatively charged particles
c) Light rays
d) Neutral rays

7. Thomson applied high voltages to gases in discharge tubes. What did his experiments prove about atoms?

a) They are made of smaller particles
b) They are indestructible solid balls
c) They cannot be broken up
d) They are composed of earth, air, fire and water

8. Following his experiments Thomson suggested a new model for the structure of atoms; he called this new model the model. In this model the atom consisted of a sphere of charge with the negatively charged electrons embedded in this positively charged sphere.

9. Rutherford's gold foil experiment resulted in the discovery of the .