Average Atomic Mass Quiz

What are isotopes?

• Different forms of a particular chemical element which differ in electron number

• Different forms of a particular chemical element which differ in atomic mass

• Variants of a particular chemical element which differ in neutron number

• Different forms of a particular chemical element which differ in proton number

Tags

NGSS.HS-PS1-8

How do isotopes differ from each other?

• number of protons

• number of electrons

• number of neutrons

• atomic mass

What is the abundance of an isotope?

• The weight of an isotope compared to other isotopes of the same element.

• Relative amount or percentage of an isotope compared to other isotopes of the same element.

• The size of an isotope compared to other isotopes of the same element.

• The charge of an isotope compared to other isotopes of the same element.

How is the average atomic mass calculated?

• Sum of isotopes' masses

• Median of isotopes' masses

• Mode of isotopes' masses

• Weighted average of isotopes' masses

Why is the average atomic mass of an element usually not a whole number?

• Different isotopes and their relative abundance

• The atomic mass is calculated using a complex formula

• The atomic mass is rounded to the nearest whole number

• The atomic mass is always a whole number

If an element has two isotopes with masses 10 amu and 12 amu, and their abundances are 25% and 75% respectively, what is the average atomic mass of the element?

• 13 amu

• 10.5 amu

• 11.5 amu

• 9 amu

If an element has three isotopes with masses 20 amu, 22 amu, and 24 amu, and their abundances are 10%, 20%, and 70% respectively, what is the average atomic mass of the element?

• 24.6 amu

• 22.4 amu

• 25.8 amu

• 23.2 amu

If an element has two isotopes with masses 5 amu and 7 amu, and their abundances are 40% and 60% respectively, what is the average atomic mass of the element?

• 5.6

• 6.8

• 7.5

• 6.2

If an element has three isotopes with masses 30 amu, 32 amu, and 34 amu, and their abundances are 25%, 50%, and 25% respectively, what is the average atomic mass of the element?

• 33

• 35

• 32

• 31

If an element has two isotopes with masses 8 amu and 10 amu, and their abundances are 60% and 40% respectively, what is the average atomic mass of the element?

• 8.8 amu

• 10.4 amu

• 9.6 amu

• 9.2 amu