3.10 Atomic Masses

What defines isotopes of an element?

• Atoms of the same element with different numbers of protons.

• Atoms of different elements with the same number of neutrons.

• Atoms of the same element with different numbers of neutrons.

• Atoms of the same element with different numbers of electrons.

What is the approximate natural abundance of Chlorine-35 and Chlorine-37, respectively?

• 50% Chlorine-35, 50% Chlorine-37

• 75% Chlorine-35, 25% Chlorine-37

• 25% Chlorine-35, 75% Chlorine-37

• 60% Chlorine-35, 40% Chlorine-37

A sample of Bromine contains 50% Bromine-79 and 50% Bromine-81. What is its relative atomic mass?

• 79.5

• 80

• 80.5

• 79

What does the relative atomic mass of an element represent?

• The mass of the most abundant isotope.

• The average mass of all protons and neutrons in an atom.

• The weighted mean mass of the isotopes of an element.

• The mass of a single atom of the element.