Isotopes and Relative Atomic Mass

Question 1

What is meant by the mass number of an atom?

Answer 1

The combined total of protons and neutrons in an atom

Question 2

Which subatomic particle do atoms of the same element always have the same number of?

Answer 2

Protons

Question 3

How can you calculate the number of neutrons in an atom?

Answer 3

Mass number - atomic number

Question 4

Give the definition of the term ‘isotopes’.

Answer 4

Atoms of the same element that have the same number of protons but a different number of neutrons

Question 5

Give the definition of the relative atomic mass of an element.

Answer 5

The average mass of one atom of the element, compared to 1/12th of the mass of one atom of carbon-12

Question 6

Explain why some elements have relative atomic masses that are not whole numbers.

Answer 6

Relative atomic mass is an average of the mass numbers of all the different isotopes of an element, taking into account the abundance of each one

Question 7

(Exam-style question)

Answer 7