Calculating 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 percent 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

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Front

What does percent abundance mean?

Back

The percentage of a specific isotope of an element compared to the total amount of that element.

Front

If an isotope has a mass of 12 amu and an abundance of 50%, what is its contribution to the average atomic mass?

Back

6 amu (12 amu * 0.50).

Front

What is the average atomic mass of an element with two isotopes: 10 amu (90% abundance) and 12 amu (10% abundance)?

Back

10.2 amu (10 * 0.90 + 12 * 0.10).

Front

How does the average atomic mass relate to the periodic table?

Back

The average atomic mass of an element is usually listed on the periodic table and reflects the weighted average of its isotopes.

Front

What is the significance of the average atomic mass in chemistry?

Back

It helps predict the behavior of elements in chemical reactions and is essential for stoichiometry.

Front

What is the average atomic mass of an element with isotopes of 14 amu (50%) and 16 amu (50%)?

Back

15 amu (14 * 0.50 + 16 * 0.50).