Atoms and Isotopes Quiz

What does the atomic number of an element refer to?

• The mass number of an atom

• The number of protons in an atom

• The atomic mass of an element

• The number of neutrons in an atom

Which term identifies each isotope of an element and is the sum of the number of protons and neutrons in the nucleus?

• Mass number

• Atomic mass

• Atomic number

• Neutron number

In a neutral atom, what is the number of electrons equal to?

• The mass number

• The atomic number

• The atomic mass

• The number of protons

Which of the following is true?

• A mass of 1 amu is nearly equal to the mass of a single electron.

• An atom’s mass depends mainly on the number of electrons it contains.

• The atomic mass of an element is the weighted average of the atomic numbers of an isotope.

• One atomic mass unit (amu) is one-twelfth the mass of a carbon-12 atom.

What is the relationship between atomic number and the number of protons?

• Atomic number is the same as atomic mass.

• Atomic number is half the number of protons.

• Atomic number equals the number of protons.

• Atomic number is the sum of protons and neutrons.

What defines an isotope of an element?

• Different number of protons and neutrons.

• Same number of protons, different number of neutrons.

• Same number of neutrons, different number of protons.

• Same number of protons, different number of electrons.

What is the atomic mass of an element?

• The weighted average mass of the isotopes of that element.

• The total number of protons and neutrons.

• The mass of a single isotope.

• The sum of all electrons in an atom.

How is the mass number of an atom calculated?

• Number of protons plus number of neutrons.

• Number of neutrons plus number of electrons.

• Number of protons minus number of neutrons.

• Number of protons plus number of electrons.

What is the primary factor that determines the chemical properties of an element?

• The number of neutrons.

• The number of protons.

• The number of electrons.

• The mass number.

How does the atomic mass of an element differ from its mass number?

• Atomic mass is a whole number, while mass number is a decimal.

• Atomic mass is the average of all isotopes, while mass number is specific to one isotope.

• Atomic mass includes only protons, while mass number includes protons and neutrons.

• There is no difference; they are the same.