Mass Number & Isotopes (AQA A-Level Chemistry): Flashcards

Number of protons in nucleus

Total protons and neutrons in nucleus

Atoms with same protons, different neutrons

$A - Z$ (mass number minus atomic number)

Equal to number of protons

Fewer electrons than protons

More electrons than protons

Same for all isotopes of an element

Different (e.g., mass, density)

Average mass of isotopes weighted by abundance