Unit 2 Quiz Flashcards Preview

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Flashcards in Unit 2 Quiz Deck (31):
1

spectrophotometry

allows you to measure the absorbance and transmittance of light energy by molecules.

2

Absorb

When light of specific wavelength (color) is passed through a solution, some of the light energy will be absorbed.

3

Transmit

The remaining light energy that is not absorbed when passed through a solution, is detected and expressed on a meter as either percent transmittance (%T) or absorbance (A).

4

Spectrophotometer

Mode button
Digital display
Wavelength knob
Sample holder
0% T-Knob
100% T Knob
Filter switch

5

6 Colors of visible light

Red
Orange
yellow
green
blue
violet

measured in nanometers (nm)

6

Red

620-750 nm

7

Orange

590-620 nm

8

Yellow

570-590 nm

9

Green

500-570 nm

10

Blue

450-500 nm

11

Violet

380-450 nm

12

Electromagnetic Radiation

Visible light is part of a large field of energy that is known as electromagnetic radiation

13

All energy travels through space in a pattern called

waves

14

smaller wavelengths=

higher energy

15

larger wavelengths=

lower energy

16

If an object is red then the white light is hitting it and all the colors but red are being

absorbed but the red light is being transmitted.

17

which color of visible light has the highest energy level?

violet

18

Examples of electromagnetic radiation

microwaves
x-rays
gamma rays
UV light
TV
radio

19

A spectrophotometer can be utilized to

determine the concentration of a solution using a set of standards of known concentration.

20

A higher concentration means

a larger amount of light will be absorbed.

21

Visible light is only a

small portion of a broad spectrum of available energy called electromagnetic radiation.

22

Electromagnetic Radiation travels in the form of a

wave, with the distance between two crests termed a wavelength.

23

Visible light consists of light wavelengths from approximately

380-720 nanometers.

24

Shorter wavelengths have

higher frequency and higher associated energy.

25

The mode button

is the left button on the top and it switches between the absorption and transmittance modes.

26

The Wavelength control knob

is the circular knob on the right side in the middle part of the spectrophotometer. The wavelength knob is used to change the wavelength.

27

The 100% T Knob

is the circular knob on the right side of the bottom part of the spectrophotometer. It is under the wavelength knob. The 100% T knob controls how much transmittance (or brightness).

28

The 0% T Knob

is the circular knob on the left side of the spectrophotometer on the bottom part. It is to the left of the 100% T knob. The 0% T knob is used to turn the spectrophotometer off and on, and controls the zero control.

29

The Sample Holder

is on the left side on the middle part of the spectrophotometer. You place the test tubes in there.

30

The Filter Switch

is on the left side on the bottom kind of underneath the spectrophotometer.

31

The Digital Display

is on the top part of the Spectrophotometer on the left side next to the mode button. It shows the wavelength, absorbance, transmittance, and a few other things?