Question

Question 4: Match the words (from the options below) to the statements by inserting the corresponding capital letter in the blank. No word is used more than once (2 Points for (i) to (xii), 1 point for (xiii).

(i) If you double the frequency of electromagnetic radiation you ______ the energy.

(ii) If you double the wavelength of electromagnetic radiation you _____ the energy.

(iii) A ____ produces an electric signal when struck by photons.

(iv) A ____ produces many wavelengths in the visible and near-IR range.

(v) The sample is contained in a _____ for ultraviolet absorbance measurements.

(vi) A ____ disperses light into its component wavelengths.

(vii) A ____ alternately transmits light from source through sample and reference.

(viii) To increase absorbance of any sample you can ____ the pathlength.

(ix) When fluorescence intensity decreases with increasing concentration, ____ is occurring.

(x) Atomic _____ requires no light source.

(xi) Atomic absorption requires a different ___________ for each element.

(xii) Before fluorescence emission of a photon occurs _______ of a photon must occur.

(xiii) A photon produced by fluorescence has a longer _____ than the photon initially absorbed.

Options A. Dynode B. Double C. Czerny-Turner Grating Monochromator D. Emission E. Photomultiplier Tube F. Concave Mirror G. Halve H. Tungsten Lamp I. Laser J. Plastic Cuvette K. Quenching L. Rotating Mirror/Beam Chopper M. Absorption N. Slit O. Quartz Cuvette P. Hollow Cathode Lamp Q. Increase R. Wavelength S. Flame T. Decrease

Answer 1

(i): The relation between frequency and energy is: E = h*

Since E is directly proportional to frequency (), when we double the frequency, the energy will also double. So B.Double

(ii): E = h*c /

Since E is inversely proportional to wavelength (), when we double the wavelength (), the energy becomes:

E' = h*c / 2 = E/2

Hence the ehergy halves. Hence G.Halve

(iii): A Photomultiplier Tube is used to detect light of very low signal. Absorption of a photon in a Photomultiplier Tube results in the emission of electron.

Hence (E).Photomultiplier Tube

(iv): (H). A Tungsten Lamp produces many wavelengths in the visible and near-IR range.

(v): The sample is contained in a (J): plastic cuvette for ultraviolet absorbance measurements.

(vi): (C). Czerny-Turner Grating Monochromator disperses light into its component wavelengths.