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 abundance.

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) + ... + (massn * abundancen)

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) contributes to the average atomic mass.

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What is the average atomic mass of an element with isotopes of 12 amu (75%) and 14 amu (25%)?

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Average Atomic Mass = (12 * 0.75) + (14 * 0.25) = 12.5 amu.

Front

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

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Isotopes have different masses, and their relative abundances affect the average atomic mass of the element.

Front

What is the average atomic mass of an element with isotopes of 20 amu (30%), 22 amu (50%), and 24 amu (20%)?

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Average Atomic Mass = (20 * 0.30) + (22 * 0.50) + (24 * 0.20) = 21.4 amu.

Front

What is the average atomic mass of silver?

Back

107.8677 amu.

Front

What is the average atomic mass of magnesium with isotopes of 24 amu (79%), 25 amu (10%), and 26 amu (11%)?

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Average Atomic Mass = (24 * 0.79) + (25 * 0.10) + (26 * 0.11) = 24.32 amu.

Front

If an isotope has a mass of 5 amu and makes up 20% of the sample, what is its contribution to the average atomic mass?

Back

1 amu (5 amu * 0.20) contributes to the average atomic mass.