Relative atomic mass

Question 1

What is the formula for calculating relative atomic mass?

Answer 1

Relative atomic mass = (mass of isotope 1 × % abundance of isotope 1 + mass of isotope 2 × % abundance of isotope 2 + …) / 100

Question 2

True or False: Relative atomic mass is a weighted average of all isotopes of an element.

Answer 2

True

Question 3

Fill in the blank: The relative atomic mass of an element is expressed in _____.

Answer 3

atomic mass units (amu)

Question 4

Which unit is commonly used to express relative atomic mass?

Answer 4

Atomic mass units (amu)

Question 5

What does the term ‘isotope’ refer to?

Answer 5

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

Question 6

Multiple Choice: Which of the following elements has a relative atomic mass of approximately 12 amu? A) Carbon B) Oxygen C) Nitrogen D) Helium

Answer 6

A) Carbon

Question 7

What is the significance of the % abundance in the relative atomic mass calculation?

Answer 7

The % abundance indicates the proportion of each isotope present in a naturally occurring sample of the element.

Question 8

True or False: The relative atomic mass of an element can be a whole number.

Answer 8

False

Question 9

Short Answer: If an element has two isotopes with masses of 10 amu (30% abundance) and 12 amu (70% abundance), what is its relative atomic mass?

Answer 9

11.4 amu

Question 10

What is the relative atomic mass of an element with only one isotope?

Answer 10

It is equal to the mass of that isotope in atomic mass units (amu).

Question 11

Formula for Relative atomic mass

Answer 11

(Mass number of isotope 1 x percent abundance of isotope 1) + (Mass number of isotope 2 x percent abundance of isotope 2) divided by 100