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.

Front

What is the significance of atomic number?

Back

The number of protons in the nucleus of an atom, which determines the element's identity.

Front

If an element has isotopes with masses of 10 amu (90%) and 11 amu (10%), what is the average atomic mass?

Back

10.1 amu.

Front

What do isotopes of an element have in common?

Back

They have the same atomic number and number of protons.

Front

What is the mass number of an isotope?

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The total number of protons and neutrons in the nucleus of an atom.

Front

How does the abundance of isotopes affect average atomic mass?

Back

Isotopes with higher abundance have a greater impact on the average atomic mass.

Front

What is the average atomic mass of an element with isotopes of 12 amu (98%) and 14 amu (2%)?

Back

12.04 amu.

Front

What is the formula for calculating average atomic mass?

Back

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