AP Calculating Avg. 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 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 two isotopes: 10 amu (20% abundance) and 12 amu (80% abundance)?

Back

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

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

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

Back

Isotopes have different masses and abundances, affecting the overall average atomic mass of an element.

Front

How does the abundance of an isotope affect its contribution to average atomic mass?

Back

Higher abundance means a greater contribution to the average atomic mass.

Front

What is the average atomic mass of an element with isotopes of 75 amu (24% abundance) and 74 amu (76% abundance)?

Back

74.76 amu (75*0.24 + 74*0.76).

Front

If an element has three isotopes with masses of 20 amu, 21 amu, and 22 amu with abundances of 50%, 30%, and 20% respectively, what is the average atomic mass?

Back

20.9 amu (20*0.50 + 21*0.30 + 22*0.20).