Atomic Structure

Question 1

What are the three subatomic particles?

Answer 1

Protons
Neutrons
Electrons

Question 2

What is the relative mass of these particles?

Answer 2

Proton = 1
Neutron = 1
Electron = negligible or 1/2000

Question 3

What are the charges of these particles?

Answer 3

Proton = +1
Neutron = 0
Electron = -1

Question 4

What was the original particle theory?

Answer 4

That matter was made up of tiny spheres called atoms and each element was made up of one atom type and couldn’t be broken down

Question 5

What was then discovered 100 years later?

Answer 5

That electrons could be removed from atoms which suggested that atoms were positively charged spheres with tiny negative electrons in them like plums pudding

Question 6

What did Rutherford and Marsden do?

Answer 6

Fired beans of tiny alpha particles at gold foil and expected positively charged alpha particles to be slightly deflected by electrons in plums pudding model

Question 7

What actually happened in the experiment and what did this mean?

Answer 7

Most alpha particles went straight through and the occasional one came back this meant that most mass of the atom must be concentrated in the centre in a tiny positively charged nucleus to repel positively charged alpha particles
Atom is mostly empty space

Question 8

What charge does an atom have?

Answer 8

No overall charge

Question 9

What is the nuclear model of the atom?

Answer 9

Nucleus is tiny but contains most mass
Nucleus contains positive protons and neutral neutrons- overall positive charge
Most of atom is empty space
Negative electrons circle nucleus
Radius of nucleus = 10000 x smaller than radius of the atom