 The weighted average of its naturally occurring isotopes. Chemical Name Atomic # Chemical Symbol Atomic Mass (Average Atomic Mass)

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Presentation transcript:

 The weighted average of its naturally occurring isotopes. Chemical Name Atomic # Chemical Symbol Atomic Mass (Average Atomic Mass)

 Multiply the mass of each isotope by its abundance to get the weighted average.

 Boron is 80.20% boron-11 (atomic mass amu) and 19.80% boron-10 (atomic mass amu). What is the average atomic mass of boron?

 Neon has 2 isotopes.  Neon-20 has a mass of amu.  Neon-22 has a mass of amu.  In an average sample of neon atoms, 90% will be neon-20 and 10% will be neon-22. Calculate the average atomic mass.