In UV/Visible Spectrophotometry, Absorption Spectra Consist of Relatively Broad Bands

question 1

Multiple Choice

In UV/Visible spectrophotometry, absorption spectra consist of relatively broad bands of absorption, whereas in atomic absorption spectrophotometry, line spectra consist of lines of absorption that are on the order of 0.001 to 0.01 nm in width.Which of the following provides the correct explanation for this difference in width of absorption bands?

• A)The methods of detection in atomic absorption spectrophotometry are much more sensitive than those utilized in UV/Visible spectrophotometry.
• B)Atomic absorption methods measure absorption characteristics of vaporized atoms, whereas UV/Visible techniques measure absorption characteristics of molecules with many bonds and chromophoric groups.
• C)The use of the flame in atomic absorption methods removes the matrix which causes broad absorption bands in UV/Visible techniques.
• D)The use of the flame in atomic absorption methods removes chemical interferences that would otherwise broaden absorption bands.

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Definitions:

Stimulus Set Point

The threshold at which a stimulus is strong enough to elicit a response or reaction.

Just Noticeable Difference

The minimum difference in stimulation that a person can detect 50% of the time, a concept also known as the threshold of sensation.

Absolute Threshold

The minimum intensity of stimulation that must be achieved in order for a stimulus to be detected 50% of the time.

Taste Cells

Specialized sensory cells located on the taste buds of the tongue, responsible for perceiving different flavors such as sweet, salty, bitter, and sour.