Unit 2 Quiz Flashcards
(31 cards)
spectrophotometry
allows you to measure the absorbance and transmittance of light energy by molecules.
Absorb
When light of specific wavelength (color) is passed through a solution, some of the light energy will be absorbed.
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).
Spectrophotometer
Mode button Digital display Wavelength knob Sample holder 0% T-Knob 100% T Knob Filter switch
6 Colors of visible light
Red Orange yellow green blue violet
measured in nanometers (nm)
Red
620-750 nm
Orange
590-620 nm
Yellow
570-590 nm
Green
500-570 nm
Blue
450-500 nm
Violet
380-450 nm
Electromagnetic Radiation
Visible light is part of a large field of energy that is known as electromagnetic radiation
All energy travels through space in a pattern called
waves
smaller wavelengths=
higher energy
larger wavelengths=
lower energy
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.
which color of visible light has the highest energy level?
violet
Examples of electromagnetic radiation
microwaves x-rays gamma rays UV light TV radio
A spectrophotometer can be utilized to
determine the concentration of a solution using a set of standards of known concentration.
A higher concentration means
a larger amount of light will be absorbed.
Visible light is only a
small portion of a broad spectrum of available energy called electromagnetic radiation.
Electromagnetic Radiation travels in the form of a
wave, with the distance between two crests termed a wavelength.
Visible light consists of light wavelengths from approximately
380-720 nanometers.
Shorter wavelengths have
higher frequency and higher associated energy.
