Isotopes and 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, resulting in different atomic masses.

Front

How is average atomic mass calculated?

Back

Average atomic mass is calculated by taking the weighted average of the masses of an element's isotopes, based on their relative abundances.

Front

What subatomic particles contribute most to an atom's mass?

Back

Protons and neutrons contribute most to an atom's mass.

Front

What is the atomic mass of an element?

Back

The atomic mass of an element is the weighted average mass of the isotopes of that element, measured in atomic mass units (amu).

Front

If an element has isotopes with masses of 10 amu (90% abundance) and 11 amu (10% abundance), what is the average atomic mass?

Back

Average atomic mass = (10 amu * 0.90) + (11 amu * 0.10) = 10.1 amu.

Front

What is the significance of the atomic number?

Back

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

Front

How many protons and neutrons are in the isotope Carbon-14?

Back

Carbon-14 has 6 protons and 8 neutrons.

Front

What is the relationship between isotopes and chemical behavior?

Back

Isotopes of an element exhibit similar chemical behavior because they have the same number of protons and electrons.

Front

What is the formula for calculating average atomic mass?

Back

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

Front

What is the average atomic mass of an element with isotopes of 12 amu (98% abundance) and 14 amu (2% abundance)?

Back

Average atomic mass = (12 amu * 0.98) + (14 amu * 0.02) = 12.04 amu.