Electromagnetic Spectrum Flashcards
What is electromagnetic radiation described as
Can be described as a wave and as a particle therefore said to have a dual nature
What is the forumla for wavelength
C=f x lambda where c is the speed of light (3.0x10 to the 8)
What happens when electromagnetic radiation is absorbed or emitted by matter
It behaves like a stream of particles, these particle are known as photons
What equation is used to calculate the energy associated with a single photon
E=hf where h is planks constant (6.63 x 10-34 Js)
What is the equation used to calculate the energy associated with one mole of photons
E=Lhc/ lambda where L is avogadros constant (6.02 x 10 to the 23 mol-1)
What happens when a photon is emitted or absorbed
The electrons within the substance gain or lose energy
Compare photons in high and low frequency radiation
Photons in high frequency radiation transfer more energy than photons in lower frequency radiation
What happens in emission spectroscopy
High temperatures are used to excite the electrons within atoms in the sample and as the electrons drop to lower energy levels photons are emitted and measured.
How is an emission spectrum of a sample produced
By measuring the intensity of light emitted at different wavelengths
What happens when photons of light energy are absorbed by atoms
Electrons move from a lower energy level to a higher one. As this happens an absorption spectrum is produced
What is used to identify and qualify elements
Each element produces a unique pattern of frequencies of radiation in both emission and absorption spectra which are used to indentify and qualify
What is used to determine unknown concentrations of an element
The concentration of an element within a sample is related to the intensity of light emitted or absorbed and that is used
What is electromagnetic radiation
A form of energy. The electromagnetic spectrum consists of many bands of electromagnetic radiation which differ in energy, wavelength and frequancy
What visible light
Form of electromagnetic radiation and is split into seven colours and colours are in the order ROY G BIV
Whats the order of the electromagnetic spectrum
Radio waves, microwaves, infrared light, visible light, ultraviolet, x-rays, gamma rays
What colours in the visible light spectrum have a higher and lower frequancy
Red end has a lower frequancy, purple end has a higher frequancy
Whats a wavelength
Is the distance between adjacent crests given by symbol lambda
Whats the frequency
Is determined by the number of wavelengths that pass a fixed point in one second, measured in hertz
What speed does the electromagnetic spectrum travel at
A constant speed, which is the speed of light 3,0x10 to the 8
Whats the formula that relates wavelength and frequancy
C= fx lambda
What do photons which have high frequencies do
Transfer larger amounts of energy than photon of lower frequencies
What happens when a beam of white light is passed through a prism
A continuous spectrum is visible
What happens when white light passes through a sample being heated
The spectrum turns out not to be continuous but a series of lines of different wavelengths and thus different colours, each line corresponds to the energy given out when excited electrons move down to a lower energy level generating photons
What does each element do
Creates its own unique spectrum with its own specific frequencies and wavelengths
