NSG 3850 Exam 4 Galen College of
Nursing Complete Exam Prep
Workbook with Rationales and
Practice Assessments 2026/2027
Question 1
Which cuvette material is most appropriate for measurements in the ultraviolet range
below 320 nm?
A. Plastic
B. Glass
C. Quartz
D. Acrylic
Correct Answer: C. Quartz
Rationale: Quartz cuvettes are required for UV spectroscopy below 320 nm because
they transmit ultraviolet light without significant absorption. Plastic and glass cuvettes
absorb UV light strongly in this region and therefore distort absorbance readings.
Glass is only suitable for wavelengths above approximately 320 nm, while plastic is
typically used for higher visible-range wavelengths (>280 nm). Quartz provides the
broadest optical transparency, making it the standard for UV work.
Question 2
Which statement best describes Electron Ionization (EI) in mass spectrometry?
A. Soft ionization producing intact molecular ions
B. Ionization by reagent gas collisions
C. Hard ionization caused by high-energy electrons
D. Ionization using laser desorption
Correct Answer: C. Hard ionization caused by high-energy electrons
Rationale: EI is a hard ionization technique where high-energy electrons directly
strike analyte molecules, producing extensive fragmentation. This fragmentation is
useful for structural identification but often destroys the molecular ion. Soft ionization
methods like chemical ionization or MALDI preserve more intact ions. EI is widely
used for small organic and inorganic compounds but is less suitable for fragile
biomolecules.
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Question 3
What is the main advantage of Chemical Ionization (CI) compared to Electron
Ionization (EI)?
A. Produces extensive fragmentation
B. Produces softer ionization with less fragmentation
C. Only works for inorganic compounds
D. Requires no reagent gas
Correct Answer: B. Produces softer ionization with less fragmentation
Rationale: Chemical ionization is a soft ionization technique that produces fewer
fragments and more intact molecular ions compared to EI. It uses reagent gases such
as methane or ammonia that are first ionized and then transfer charge to analyte
molecules. This reduces fragmentation and improves molecular weight determination.
EI, in contrast, produces extensive fragmentation due to high-energy electron impact.
Question 4
Which reagent gases are commonly used in chemical ionization?
A. Oxygen and nitrogen
B. Methane, ammonia, isobutane
C. Helium and argon
D. Hydrogen and chlorine
Correct Answer: B. Methane, ammonia, isobutane
Rationale: CI uses reagent gases like methane, ammonia, or isobutane, which are
ionized first in the chamber and then interact with analyte molecules. These gases
help produce soft ionization conditions and can generate protonated or deprotonated
species. Inert gases like helium are typically used as carrier gases rather than reagent
gases.
Question 5
Which mass analyzer measures ions based on time-of-flight?
A. Quadrupole
B. Ion trap
C. TOF analyzer
D. Magnetic sector
Correct Answer: C. TOF analyzer
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Rationale: Time-of-flight (TOF) analyzers separate ions based on their flight time
through a field-free region. Lighter ions reach the detector faster than heavier ions.
Quadrupoles filter ions by stability in oscillating fields, while ion traps confine ions in
electromagnetic fields. TOF instruments are valued for high speed and high mass
accuracy.
Question 6
Which is a key advantage of Flame Atomic Absorption Spectroscopy (FAAS)?
A. Extremely high sensitivity for trace analysis
B. Rapid and cost-effective analysis
C. Requires no calibration
D. Works only for organic compounds
Correct Answer: B. Rapid and cost-effective analysis
Rationale: FAAS is widely used because it is fast, relatively inexpensive, and suitable
for routine elemental analysis. However, it is less sensitive than graphite furnace AAS
or ICP-MS. It is primarily used for moderate concentration ranges and requires
calibration standards for accurate quantification.
Question 7
Which technique is most appropriate for ultra-trace elemental analysis?
A. Flame AAS
B. UV-Vis spectroscopy
C. ICP-MS
D. Gravimetric analysis
Correct Answer: C. ICP-MS
Rationale: ICP-MS provides extremely high sensitivity and is capable of detecting
trace and ultra-trace elemental concentrations. Flame AAS lacks sufficient sensitivity
for such low levels. ICP-MS also allows multi-element detection simultaneously,
making it ideal for environmental and biological trace analysis.
Question 8
What is the correct Beer-Lambert Law equation?
A. A = log(T)
B. A = εbc
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C. A = P/Po
D. A = λc
Correct Answer: B. A = εbc
Rationale: The Beer-Lambert Law defines absorbance as proportional to molar
absorptivity (ε), path length (b), and concentration (c). This relationship is
fundamental in UV-Vis spectroscopy. The other options represent transmittance or
incorrect relationships.
Question 9
What is the correct relationship for transmittance?
A. T = A/c
B. T = P/Po
C. T = εb
D. T = log(P)
Correct Answer: B. T = P/Po
Rationale: Transmittance is defined as the ratio of transmitted light intensity (P) to
incident light intensity (Po). It is a direct measure of how much light passes through a
sample. Absorbance is derived from transmittance using a logarithmic relationship.
Question 10
Which ionization method is considered a soft ionization technique?
A. Electron ionization
B. MALDI
C. Thermal ionization
D. Plasma ionization
Correct Answer: B. MALDI
Rationale: MALDI (Matrix-Assisted Laser Desorption Ionization) is a soft ionization
technique that produces mostly intact molecular ions with minimal fragmentation. It is
particularly useful for large biomolecules like proteins. EI is a hard ionization method
that produces extensive fragmentation.
Question 11
What is the main purpose of MALDI matrix material?