Isotopes & Average Atomic Mass

Front

What is an isotope?

Back

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons.

Front

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

Back

Average atomic mass is calculated by multiplying the mass of each isotope by its relative abundance (as a decimal) and summing the results.

Front

What is the mass number of an atom?

Back

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

Front

How many protons are in an atom of Lithium-7?

Back

An atom of Lithium-7 has 3 protons.

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom and determines the element's identity.

Front

If an isotope has a mass number of 14 and 6 protons, how many neutrons does it have?

Back

It has 8 neutrons (14 - 6 = 8).

Front

What is the significance of the percent abundance of isotopes?

Back

Percent abundance indicates how common each isotope is in nature, which affects the average atomic mass of the element.

Front

Which isotope of Carbon has 6 neutrons?

Back

Carbon-12 has 6 neutrons.

Front

What is the relationship between protons and electrons in a neutral atom?

Back

In a neutral atom, the number of protons equals the number of electrons.

Front

How many neutrons are in Carbon-14?

Back

Carbon-14 has 8 neutrons (14 - 6 = 8).