Chapter 1 Multiple Choice Questions

. A mass spectrometer measures:

mass

mass to charge ratio

molecular weight

molecular size

. The unit of atomic and molecular mass is:

the gram

the mole

the dalton

the nanogram

. The mass of an ion or molecule calculated using isotope mass and rounded to the nearest integer value is known as:

nominal mass

monoisotopic mass

isotopically averaged mass

mass defect

. The correct form of the Lorentz force law is:

F = z(E + B)

F = ze(E + B)

F = ze(E + v x B)

F = mze(E + v x B)

. The isotopic separation of a quadruply-charged ion ([M+4H]⁴⁺) on the m/z scale is:

1

2

0.5

0.25

. Which part of a mass spectrometer separates ions according to their mass to charge ratio?

Ion source

Mass analyser

Sample inlet

Detector

. What is responsible for the difference in mass between a ³²S atom and two ¹⁶O atoms?

Nuclear binding energy

Newton's second law

The mass of an electron

The mass of a proton

. What is usually represented by the vertical axis in a mass spectrum?

m/z

Peak area

Monoisotopic atomic mass

Relative ion abundance

. What does the base peak in a mass spectrum refer to?

The molecular ion

The most abundant ion in a mass spectrum

One of the fragment ions in a mass spectrum

The lowest intensity ion in a mass spectrum

. In what year was the Nobel Prize for Chemistry awarded in recognition of the importance of ESI and MALDI ionization development?

1907

1954

2010

2002

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