Atomic Structure and Composition Quiz

Which component of an atom determines its chemical identity?

• Mass number
• Electron configuration
• Atomic number
• Neutron count

The mass number represents the total number of which two subatomic particles?

• Protons and electrons
• Electrons and neutrons
• Neutrons and positrons
• Protons and neutrons

In the atomic model, what represents the total number of protons in an atom's nucleus?

• Electron count
• Isotope number
• Atomic number
• Mass number

Two atoms with the same number of protons but different neutron counts are called:

• Ions
• Isotopes
• Isotherms
• Isomers

Which atomic model introduced the concept of electron shells and orbitals?

• Thomson's model
• Bohr's model
• Rutherford's model
• Dalton's model

What happens to an atom's atomic number if a proton is removed?

• It remains the same
• It becomes unstable
• It becomes an ion
• It changes to a different element

In the notation ¹²C, what does the superscript represent?

• Number of protons
• Number of electrons
• Atomic weight
• Mass number

Which subatomic particle contributes to mass but not to the atomic number?

• Positron
• Neutron
• Electron
• Proton

The modern atomic model most closely resembles which scientist's description?

• Bohr
• Rutherford
• Thomson
• Dalton

What determines an atom's chemical reactivity?

• Mass number
• Proton count
• Neutron count
• Electron configuration