Unit 1 Flashcards
frequency
peaks per second in hertz (Hz) or s^-1… variable is v
speed of light
assuming a vacuum for this course… variable is c
wavelength
length from peak/trough of wave. can be nanometers or meters for units (use 10^9/10^-9 as conversion)
Electromagnetic Radiation Spectrum
shorter wavelength, higher frequency, higher energy
c= v(lambda)
inversely proportional c= speed of light constant v= frequency (waves per second) lambda= wavelength - don't forget to convert wavelength to match units of light
energy levels
are called shells, orbits or symbolized by “n”. lower orbitals have less energy ex (n= 1 has less energy than n=4)
distance between energy levels
- energy levels get closer together the further you go
electron goes down an orbital
- electron loses energy so it will emit light of wavelength equal to energy lost
electron goes up an orbital
electron absorbs energy equal to wavelength of light given to it
absorption
electron goes up shell due to energy given to it
emission
electron goes down shell due to energy emitted
continuous spectrum of light (line spectrum)
shows rainbow
- all wavelengths on spectrum are visible light
emission lines (line spectrum)
few colours on a black backdrop visually
- the colours are wavelengths of light emitted when a gas atom was originally excited but that then electron emits the light was it goes back to rest state
absorption (line spectrum)
while light is going through a gas sample of an element, the electron would absorb some energy of that light causing
at what speed does all electromagnetic radiation move at?
the speed of light
electromagnetic radiation and energy transfer
ex. when molecules absorb radiation, it increases the energy of the molecules causing more collisions and a rise in temperature (case of microwave at least)
planck’s quantum theory
energy can only be gained or lost in whole number multiples of hv where h is a constant. can find energy absorbed or released
quantum
small packet of energy that can only occur in discrete units. system can only transfer energy in whole quanta thus energy seems to have particulate properties.
photosns
einstein discovered that electromagnetic radiation can be seen as a stream of particles called photons
delta e=nhv OR delta e=hc/(lambda)
gives the amount of a single quantum (the energy of a photon of light)
n= an integer h= planck's constant v= frequency
dual nature of light
electromagnetic radiation can show certain characteristics of particulate matter which is called dual nature
de Broglie’s equation
lambda= h/mv
lambda= h/mv
used to calculate the wavelength for a particle
- h=planck’s constant
m= mass
v= AHAH it is velocity
1 joule equals
1 kg times m^2 / s^2