SC3 - Atomic Structure

Question 1

What is all matter made of?

Answer 1

Atoms

Question 2

What are the subatomic particles in an atom?

Answer 2

Electron
Proton
Neutron

Question 3

State the charges and masses of each subatomic particle.

Answer 3

Name = Charge = Mass
Electron = -1 = 1/1835
Proton = +1 = 1
Neutron = 0 = 1

Question 4

What was Rutherford’s atomic model and how did he come up with it?

Answer 4

He discovered that the atom was mostly empty and there was a nucleus. He found out by firing alpha particles at a gold foil. Most went through. Some deflected and little bouncing back. This meant that most of the atom was empty and it had a central nucleus inside it.

Question 5

What is the atomic number and mass?

Answer 5

Atomic Number = number of protons or electrons
Atomic mass = Number of protons + neutrons

Question 6

How do you label the atomic symbols?

Answer 6

The atomic mass is on the top left of the symbol.
The atomic number is on the bottom left of the symbol.

Question 7

What is it called when 2 or more atoms have the same atomic number but have different atomic masses?

Answer 7

An isotope

Question 8

What is the RAM?

Answer 8

Mass relative to a carbon-12 atom whose mass is exactly 12.

Question 9

How do you calculate RAM (Ar) from the abundances of different isotopes?

Answer 9

total mass / total number of atoms
total number of atoms is usually 100
total mass/100

Question 10

Exam Q -
Neon gas has a relative atomic mass of 20.2 and is made up of 2 atoms:
- Neon-20
- Neon 22
Explain which of these 2 is more abundant
(3 marks)

Answer 10

Ne-20 is the most abundant because the relative atomic mass of an element is the mean (average) mass of its atoms. The mean mass will be closest to the mass
number of the most abundant atom