Average Atomic Mass

Front

What is average atomic mass?

Back

The weighted average mass of an element's isotopes, measured in atomic mass units (amu).

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 average atomic mass of silver?

Back

107.8677 amu.

Front

If 4.35% of atoms have a mass of 39.946 amu, 83.79% have a mass of 41.941 amu, 9.50% have a mass of 42.941 amu, and 2.36% have a mass of 43.939 amu, what is the average atomic mass of atom X?

Back

41.97 amu.

Front

What is the average atomic mass of silicon?

Back

28.09 amu.

Front

An element has two isotopes: one is 10.013 amu (19.9% abundant) and the other is 11.01 amu (80.1% abundant). What is the average atomic mass?

Back

10.812 amu, which is Boron.

Front

Which isotope has 82 neutrons?

Back

Ba-138.

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 relative abundance?

Back

The percentage of a particular isotope in a naturally occurring sample of an element.

Front

What is the significance of atomic mass units (amu)?

Back

A unit of mass used to express atomic and molecular weights, where 1 amu is defined as one twelfth of the mass of a carbon-12 atom.