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 is average atomic mass calculated?

Back

Average atomic mass = (mass of isotope 1 × abundance of isotope 1) + (mass of isotope 2 × abundance of isotope 2) + ...

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 does the term 'abundance' refer to in isotopes?

Back

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

Front

If an element has two isotopes with masses of 10 amu and 12 amu, and their abundances are 50% each, what is the average atomic mass?

Back

Average atomic mass = (10 amu × 0.5) + (12 amu × 0.5) = 11 amu.

Front

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

Back

Atomic mass units provide a standard unit of mass for atoms and molecules, allowing for easier comparison.

Front

How do you determine if two atoms are isotopes?

Back

Two atoms are isotopes if they have the same number of protons but different numbers of neutrons.

Front

What is the average atomic mass of an element with isotopes of 35 amu (75% abundance) and 37 amu (25% abundance)?

Back

Average atomic mass = (35 amu × 0.75) + (37 amu × 0.25) = 35.5 amu.

Front

What is the relationship between isotopes and the periodic table?

Back

Isotopes of an element are represented by the same element symbol but may have different atomic masses.

Front

What is the formula for calculating the average atomic mass of an element with three isotopes?

Back

Average atomic mass = (mass1 × abundance1) + (mass2 × abundance2) + (mass3 × abundance3).