Isotopes and Calculating Atomic Mass

Front

What are isotopes?

Back

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses.

Front

What quantities vary between isotopes of an element?

Back

Neutrons and atomic mass.

Front

How do you calculate the average atomic mass of an element with multiple isotopes?

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 an element with two isotopes: 10.013 amu (19.9% abundance) and 11.01 amu (80.1% abundance)?

Back

10.812 amu.

Front

What is the significance of atomic mass in isotopes?

Back

Atomic mass indicates the average mass of an element's isotopes, weighted by their natural abundance.

Front

Which isotope of lead is likely to be the most abundant if the average atomic mass is 207.2?

Back

Lead-207.

Front

What is the relationship between protons, neutrons, and atomic mass in isotopes?

Back

The atomic mass is the sum of protons and neutrons; different isotopes have varying numbers of neutrons.

Front

If an element has 33 protons, what is its atomic number?

Back

33.

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which defines the element.

Front

What are the two main types of isotopes?

Back

Stable isotopes and radioactive isotopes.