Atomic & mass number + isotopes

    Cards (5)

    • What is atomic number?

      The number of protons in an atom's nucleus.
    • What is mass number?

      Total number of protons and neutrons in an atom.
    • What are isotopes?
      Isotopes are atoms of the same element that have different numbers of neutrons.
    • What is relative atomic mass?

      The average mass of one atom of the element compared to 1/12 of the mass of one atom of carbon -12.
    • What is the formula to work out relative atomic mass from isotopic abundances?

      relative atomic mass (Ar) = sum of (isotope abundance x isotope abundance) ÷ sum of abundances of all isotopes.