A mass spectrum of a monatomic sample gives four isotopic peaks, each corresponding to singly charged ions.
m/z (amu) Relative abundance
70 14.0 %
72 30.0 %
73 16.0 %
74 40.0 %
The instrument has an uncertainty of ±0.10 amu in the average-mass determination. Which element is the best match for the sample?
a) Selenium, 78.96 amu
b) Germanium, 72.63 amu
c) Gallium, 69.72 amu
d) Arsenic, 74.92 amu