Fundamental Particles

Question 1

How did the periodic table develop over time?

Answer 1

• 1661: Robert Boyle proposed chemical elements.
• 1803: John Dalton elements composed of individual atoms
• 1896: Henri Becquerel discovered Radioactivity
• 1911: Ernest Rutherford found most mass and positive charge was in central nucleus

Question 2

Properties of sub-atomic particles

Answer 2

Proton

• mass = 1
• charge = +1 In Nucleus

Electron

• mass = 0
• charge = -1 Around Nucleus

Neutron

• mass = 1
• charge = 0 In Nucleus