1.1 Atomic Structure & 1.2 Mass number, atomic number and Isotopes

Question 1

What are ‘nucleons’?

Answer 1

The protons and neutrons that make up the nucleus of an atom

Question 2

What is the relative mass of a proton?

Answer 2

1

Question 3

What is the relative mass of a neutron?

Answer 3

1

Question 4

What is the relative mass of an electron?

Answer 4

1/1840

Question 5

What is the mass number?

Answer 5

The total number of both protons and neutrons in an atom

Question 6

What is the atomic number?

Answer 6

The total number of protons in an atom

Question 7

Iron is a major component of steel, a major industrial material. Today, most of the iron is mined from its ore in Western Australia. State the number of subatomic particles in iron. Mr= 55.8
Atomic number= 26

Answer 7

Protons= 26

Neutrons= (56-26)= 30

Electrons= 26

Question 8

Explain how the protons and neutrons in the centre of the atom are held together

Answer 8

They are held together by strong nuclear force. This is stronger than the strong electrostatic forces of attraction that hold the protons and the electrons together.

Question 9

Define ‘isotope’

Answer 9

Atoms with the same number of protons and electrons but a different number of neutrons

Question 10

Define ‘relative atomic mass’

Answer 10

The mass of the isotope relative to 1/12 of the mass of carbon12

Question 11

How is an atom of 37Cl different to 35Cl in terms of protons, neutrons and electrons?

Answer 11

37Cl has 2 more neutrons than 35Cl.

Question 12

How is an atom of 37Cl the same as 35Cl in terms of protons, neutrons and electrons?

Answer 12

37Cl has the same number of protons and electrons than 35Cl