Isotopes and Relative 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 relative atomic mass defined?

Back

Relative atomic mass is the weighted average mass of an element's isotopes compared to 1/12th the mass of a carbon-12 atom.

Front

What does a mass spectrum show?

Back

A mass spectrum displays the distribution of isotopes of an element based on their mass-to-charge ratio, indicating the relative abundance of each isotope.

Front

How many isotopes does neon have according to its mass spectrum?

Back

Neon has 3 isotopes.

Front

Which isotope of lithium has 4 neutrons?

Back

Li-7 has 4 neutrons.

Front

How do you calculate average atomic mass?

Back

Average atomic mass is calculated by multiplying the mass of each isotope by its relative abundance (as a decimal), summing these values, and then rounding as necessary.

Front

What is the average atomic mass of the isotopes: 25Y (11%), 32Y (39%), 29Y (22%), 30Y (28%)?

Back

The average atomic mass is 30.0.

Front

What is the atomic mass of silicon based on its isotopes: 27.9 amu (92.2%), 28.9 amu (4.7%), 29.9 amu (3.1%)?

Back

The atomic mass of silicon is 28.0.

Front

Which isotope of neon is most abundant?

Back

Ne-20 is the most abundant isotope of neon.

Front

What is the significance of relative abundance in isotopes?

Back

Relative abundance indicates how much of each isotope is present in a sample, which affects the average atomic mass of the element.