Luminescence

Question 1

is the emission of light by a substance

Answer 1

Luminescence

Question 2

It occurs when an electron returns to the electronic ground state from an excited state and loses its excess energy as a photon.

Answer 2

Luminescence

Question 3

Three types of luminescence

Answer 3

Fluorescence
Phosphorescence
Chemiluminescence

Question 4

When a beam of light is incident on certain substances they emit visible light or radiations.

Answer 4

Fluorescence

Question 5

starts immediately after the absorption of light and stops as soon as the incident light is cut off

Answer 5

Fluorescence

Question 6

When light radiation is incident on certain substances they emit light continuously even after the incident light is cut off.

Answer 6

Phosphorescence

Question 7

Measurement of the Fluorescence

Answer 7

Fluorometry

Question 8

is the production of light from a chemical reaction

Answer 8

Chemiluminescence

Question 9

The excitation of the substance does not involve electromagnetic radiation and no monochromators are needed, instead the excitation energy comes from a chemical or electrochemical reaction

Answer 9

Chemiluminescence

Question 10

Light signal is measured against a completely dark background

Involves the_____ of an organic compound

Answer 10

oxidation

Chemiluminescence

Question 11

is a physical phenomenon that results from the interaction of light with particles in solution.

Answer 11

Light scattering

Question 12

Unlike fluorescence emission, the wavelength of the_____ light is the same as that of the incident light.

Answer 12

scattered

Question 13

Measures the amount of light blocked in a particulate suspension

|
V in light transmission

Answer 13

Turbidimetry

Question 14

Measures the amount of light scattered in a particulate auspension at 90 degree angle

Answer 14

Nephelometry

Question 15

the amount of light passing through a solution is measured.

Answer 15

Turbidimetry

Question 16

The higher the____, the smaller the quantity of light transmitted (i.e. more light is absorbed).

Answer 16

turbidity

Question 17

Any ________ or ______can be used as a turbidimeter, without modification.

Answer 17

spectrophotometer or photometer

Question 18

useful method to determine the concentration of solutions that contains particles too large for absorption spectrometry

Answer 18

Nephelometry

Question 19

the detecting cell is placed at right angles to the light source, to measure light scattered by particles.

Answer 19

Nephelometry

Question 20

The instrument is called a ‘_______ or ________’ A spectrophotometer can be used, however, a special attachment is required for nephelometry.

Answer 20

Nephelometer’ or a ‘Nephelometric Turbidimeter

Question 21

Mercury arc lamp

Answer 21

Nephelometry

Question 22

Tungsten lamp

Answer 22

Turbidimetry

Question 23

Scattered light is measured

Answer 23

Nephelometry

Question 24

Light transmitted is measured

Answer 24

Turbidimetry

Question 25

Measured at 90 deg angle

Answer 25

Nephelometry

Question 26

Measured in a straight line

Answer 26

Turbidimetry

Question 27

PMT is the detector

Answer 27

Nephelometry

Question 28

Photocell is the detector

Answer 28

Turbidimetry

Question 29

FACTORS THAT AFFECT LIGHT SCATTER

Answer 29

Particle size
Concentration of particles
MW of particles
Wavelength dependence

Question 30

THREE (3) TYPES OF SCATTERED LIGHTS:

Answer 30

Rayleigh
MIE
Rayleigh Debye

Question 31

Light symmetrically scattered around the particle

Answer 31

RAYLEIGH

Question 32

Wavelength of light > particle size

Answer 32

Rayleigh

Question 33

Light scatters backward but appears forward due to destruction out of phase background scatter

Answer 33

MIE

Question 34

Wavelength of light < particle size

Answer 34

MIE

Question 35

Antigen-antibody reactions

Answer 35

RAYLEIGH DEBYE

Question 36

More forward light scatter

Answer 36

RAYLEIGH DEBYE

Question 37

Wavelength of light = particle size

Answer 37

RAYLEIGH DEBYE