Relative Mass (VCE SSCE Chemistry): Flashcards

Carbon-12 ($^{12}$C), assigned exactly 12 units

Mass of an isotope compared to carbon-12 (= 12 units)

Atoms of same element with different numbers of neutrons

They contain different numbers of neutrons

Percentage of an isotope found in natural environment

Isotope masses and their relative abundances

Number of peaks = number of isotopes present

Weighted average of isotopic masses on $^{12}$C scale

$\frac{(mass \times \% abundance) + ...}{100}$ for all isotopes

Isotopes occur in unequal amounts; abundant ones contribute more