CHEM FINAL REVIEW Average Atomic Mass

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 relative abundance (as a decimal), then sum these values.

Front

What is an isotope?

Back

Atoms of the same element that have the same number of protons but different numbers of neutrons, resulting in different masses.

Front

If an isotope has a mass of 10 amu and makes up 50% of the sample, what is its contribution to the average atomic mass?

Back

5 amu (10 amu * 0.50).

Front

What is the formula for calculating average atomic mass?

Back

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

Front

What does 'amu' stand for?

Back

Atomic Mass Unit, a standard unit of mass that quantifies mass on an atomic or molecular scale.

Front

If 40% of an element's isotopes have a mass of 12 amu and 60% have a mass of 14 amu, what is the average atomic mass?

Back

13.2 amu (0.40*12 + 0.60*14).

Front

What is the significance of average atomic mass in chemistry?

Back

It helps predict how elements will react and combine with others based on their mass.

Front

What is the average atomic mass of an element with isotopes of 1 amu (50%) and 2 amu (50%)?

Back

1.5 amu.

Front

How does the abundance of isotopes affect average atomic mass?

Back

Higher abundance of a heavier isotope increases the average atomic mass.