Mass Spectrometry

Reorder the steps to show the process of a mass spectrometer.

• Deflect

• Accelerate

• Detect

• Ionise

Which species would get deflected by the greatest degree in the mass spectrometer?

• ¹²C⁺
• ¹³C⁺
• ¹³C²⁺
• ¹⁴C⁺

What do the heights of the peaks represent in the mass spectrum?

• number of isotopes
• relative abundance of each isotope
• average atomic mass
• charge:mass ratio

What is the average atomic mass for this element?

• 10 amu
• 10.8 amu
• 19.9 amu
• 11 amu

The average atomic mass rhenium, Re, is 186.21 amu. If 37.1% of rhenium has mass# = 185, what is the other stable isotope?

• Rhenium-183
• Rhenium-181
• Rhenium-187
• Rhenium-189

Boron has two stable isotopes: ¹⁰B (20%) and ¹¹B (80%). Draw what the mass spectra for boron would look like.

Answer explanation

This is the mass spectrum for gallium. Calculate the relative atomic mass of this sample of gallium. Give your answer to two decimal places.

A scientist examined an isotopically enhanced solution of hydrogen chloride, which contained 4% deuterium ( ²H ) and regular abundances of chlorine isotopes. Sketch what the mass spectrum of this sample would look like.

Answer explanation

Around 1.16% of the carbon in our world is the isotope carbon-13. Assuming that the other isotopes of carbon and oxygen are negligible in abundance, draw the mass spectra for a sample of carbon monoxide.

Answer explanation

Bromine has two naturally occurring isotopes, bromine-79 (51%) and bromine-81 (49%). Draw the mass spectrum for bromine.

Answer explanation