Intro to electromagnetic spectrum Flashcards
What is spectroscopy?
The study of the interaction between radiation and matter
Larger wavelength …
Lower frequency
Smaller wavelength …
Higher frequency
What are the 5 waves looked at?
NMR Microwave IR UV/Vis X-ray
What does NMR involve?
Nuclear spin
What do microwaves excite?
Molecular rotations
What does IR excite?
Molecular vibrations
What does UV/Vis excite?
Valence and outer electrons
What does x ray excite?
core electrons
What does white light contain?
Contains all colours at equal intensity
What colour do you see if you do either emission or absorption?
The same colours
As long as the material is the same
What are the two ways spectra can be measured?
Absorption or emission
How can most lines in a spectrum be observed in emission?
By heating gases of various elements
What are the 5 wave properties of light?
Propagation direction Electrical component Magnetic field Electric field Magnetic component
Where is the magnetic component in respect to the electrical component?
90 degrees to it
What is the equation for the speed of light?
c = wavelength x frequency
What are the two types of interference of light?
Destructive
Constructive
What is destructive interference?
The maxima of two waves are 180 degrees out of phase
What is constructive interference?
The two waves are in phase with each other
What is a diffraction grating?
Finely grooved surface which can diffract light
What does diffraction depend on?
Colour of light
What happens when an atom moves from higher energy to lower energy?
It emits light
What is the excited state?
Any state of a system with an energy higher than the ground state
What is the ground state?
The state of a system with the lowest possible energy
