Answer:
Five peaks
Explanation:
GaAs would show two peaks:
Ga-69 + As-75 = 144
Ga-71 + As-75 = 146
Their intensities are in the ratio 60 : 40 = 100:67.
Ga₂S₂ would show three peaks:
Ga-69 + Ga-69 + 2As-75 = (Ga-69)₂(As-75)₂ = 288
Ga-69 + Ga-71 + 2As-75 = (Ga-69)(Ga-71(As-75)₂ = 290
Ga-71 + Ga-71 + 2As-75 = (Ga-71)₂(As-75)₂ = 292
Their relative intensities are in the ratio
(60 + 40)² = 60² : 2×60×40 : 40² = 3600 : 4800 : 1600 = 75 : 100 : 33
A spectrum of a mixture of GaAs and Ga₂As₂ would show five peaks:
Two at m/e 144 and 146 with intensity ratios 100: 67 and
Three at m/e 288, 290, and 292 with intensity ratios 75:100 :33.
We cannot predict the absolute sizes of the peaks because we do not know the relative amounts of GaAs and GaAs₂.
