Average Atomic Mass Review

Front

What is average atomic mass?

Back

The weighted average of the masses of an element's isotopes, taking into account their relative abundances.

Front

How do you calculate average atomic mass?

Back

Multiply the mass of each isotope by its percent abundance (as a decimal), then sum these values.

Front

What is the formula for calculating average atomic mass?

Back

Average Atomic Mass = (mass1 * abundance1) + (mass2 * abundance2) + ...

Front

If an isotope has a mass of 12 amu and an abundance of 50%, what is its contribution to the average atomic mass?

Back

6 amu (12 amu * 0.50).

Front

What is the average atomic mass of an element with isotopes of 10 amu (20% abundance) and 12 amu (80% abundance)?

Back

11.6 amu (10*0.20 + 12*0.80).

Front

What is an isotope?

Back

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

Front

What is the significance of isotopes in calculating average atomic mass?

Back

Isotopes contribute differently to the average atomic mass based on their abundance and mass.

Front

What is the average atomic mass of an element with isotopes of 14 amu (25% abundance) and 16 amu (75% abundance)?

Back

15.5 amu (14*0.25 + 16*0.75).

Front

What is the average atomic mass of an element with isotopes of 54 amu (6% abundance), 56 amu (92% abundance), and 57 amu (2% abundance)?

Back

55.9 amu.

Front

What is the average atomic mass of Boron with isotopes of 10.013 amu (19.9% abundance) and 11.01 amu (80.1% abundance)?

Back

10.812 amu.