AP Chemistry / Unit 1: Atomic Structure and Properties
1.2 Mass Spectra of Elements
Notes
A mass spectrum shows the isotopes of an element and their relative abundance. The average atomic mass is the weighted average.
- Isotopes have the same protons but different neutrons.
Practice
An element is 75% mass 35 and 25% mass 37. Average atomic mass:
$0.75(35)+0.25(37)$.
Peaks in a mass spectrum show:
Mass on the $x$-axis, abundance on the $y$-axis.
Isotopes of an element differ in their number of:
Same element, different mass.
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