Calculating Average Atomic Mass

Front

What is average atomic mass?

Back

The average atomic mass is 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

To calculate average atomic mass, 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) + ... + (massn * abundancen)

Front

What is an isotope?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses.

Front

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

Back

The contribution is 10 amu * 0.50 = 5 amu.

Front

What is the significance of relative abundance in calculating average atomic mass?

Back

Relative abundance indicates how common each isotope is in nature, affecting the overall average atomic mass.

Front

What happens if you have isotopes with equal abundance?

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If isotopes have equal abundance, the average atomic mass will be the simple average of their masses.

Front

Can average atomic mass be a non-integer value?

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Yes, average atomic mass can be a non-integer value because it is a weighted average of isotopes with different masses.

Front

What is the average atomic mass of an element with isotopes of 10 amu (50%) and 12 amu (50%)?

Back

Average Atomic Mass = (10 amu * 0.50) + (12 amu * 0.50) = 11 amu.

Front

What is the average atomic mass of an element with isotopes of 20 amu (25%) and 22 amu (75%)?

Back

Average Atomic Mass = (20 amu * 0.25) + (22 amu * 0.75) = 21.5 amu.