Atom Structure - How Atoms Differ

Multiple Choice

Who discovered that atoms of an element contain a unique positive charge in their nucleus?

• Dmitri Mendeleev

• Henry Moseley

• Marie Curie

• Ernest Rutherford

Fill in the Blanks

The atomic number is equal to the number of

in an atom.

Multiple Choice

What determines the order of elements in the periodic table?

• Atomic mass

• Number of neutrons

• Atomic number

• Number of electrons

Multiple Select

Which of the following statements are true about atomic number?

• It equals the number of protons in an atom.

• It equals the number of electrons in a neutral atom.

• It determines the element's position in the periodic table.

• It is always greater than the atomic mass.

Multiple Choice

If an atom has 30 protons, what is its atomic number and how many electrons does it have (assuming it is neutral)?

• Atomic number 30, 30 electrons

• Atomic number 8, 8 electrons

• Atomic number 82, 82 electrons

• Atomic number 12, 12 electrons

Multiple Choice

Which subatomic particle has a relative mass of 1/1840 and a negative electric charge?

• Electron

• Proton

• Neutron

• Positron

Fill in the Blanks

How does the difference in the number of neutrons among atoms of the same element affect the element?

Multiple Choice

Based on the diagrams, what is the main difference between Carbon-12, Carbon-13, and Carbon-14?

• The number of neutrons in the nucleus

• The number of protons in the nucleus

• The number of electrons in the atom

• The type of element

Multiple Select

What information do you need to determine the number of neutrons in an isotope? Select all that apply.

• Atomic number

• Mass number

• Number of electrons

• Number of protons

Multiple Choice

Which of the following best explains how the weighted average atomic mass of chlorine is calculated from its isotopes?

• By adding the atomic masses of all isotopes and dividing by the number of isotopes.

• By multiplying the atomic mass of each isotope by its percent abundance and summing the results.

• By taking the isotope with the highest abundance as the atomic mass.

• By averaging the percent abundances of the isotopes.