Question

Bromine has two isotopes, Br79 and Br81. The isotopes occur in a 50:50 (1:1) ratio. Given that the mass spectrum of bromine contains peaks for both bromine atoms and diatomic bromine molecules, predict the number of peaks in the spectrum. What would be the relative height of the atomic peaks

Answer 1

Answer:

There will be 3 peaks.

Relative height of the atomic peaks would be; 158, 160 and 162

Explanation:

We are told that Bromine has two isotopes namely 79Br and 81Br in a 1 : 1 ratio (50 : 50).

This means that a compound which contains 1 bromine atom will have two peaks in the molecular ion region but it depends on which bromine isotope is contained in the molecular ion.

Thus;

Relative height of atomic peaks is given by;

m/z = 79Br¯ 79Br+ = 158

79Br¯ 81Br+ = 160

81Br¯ 81Br+ = 162