Atomic Structure Quiz

Where is most of an atom’s mass located?

• In the electrons

• In the nucleus

• In the electron cloud

• Evenly throughout the atom

What unit is used to measure atomic mass?

• Gram

• Kilogram

• Atomic mass unit (amu)

• Mole

How is 1 amu defined?

• One-tenth the mass of a hydrogen atom

• Equal to the mass of a neutron

• One-twelfth the mass of a carbon-12 atom

• Equal to the mass of an electron

What does the atomic number of an element represent?

• Number of neutrons

• Number of protons

• Mass number

• Average atomic mass

How is the mass number of an atom calculated?

• Protons × Neutrons

• Protons + Neutrons

• Protons – Neutrons

• Electrons + Protons

What are isotopes?

• Atoms with different numbers of protons

• Atoms with the same number of neutrons

• Atoms of the same element with different numbers of neutrons

• Atoms with the same mass number

Which statement is true about electrons compared to protons and neutrons?

• Electrons are heavier than protons

• Electrons have negligible mass

• Electrons determine the mass number

• Electrons are located in the nucleus

Why do scientists calculate the average atomic mass of an element?

• To find the mass of the heaviest isotope

• To account for all naturally occurring isotopes and their abundances

• To measure only the most common isotope

• To ignore isotopes with radioactive decay

If an element has 6 protons and 8 neutrons, what is its mass number?

• 6

• 8

• 12

• 14