Electrons and energy levels Flashcards
How can you work out the energy of a photon?
E=hf or E=hc/lambda
What is planck’s constant?
6.63*10^-34
What is a photon?
A photon is the name given to a discrete packet of electromagnetic energy
How do you work out the work done in ev?
W = VQ
How do you convert from Electron volts to joules?
multiply the electron volt by 1.9*10^-19
Can an electron travel from n=2 (-3ev) to n=1 (-5ev) when it emits a photon of energy 3ev?
No because the difference between n=2 and n=2 is 2ev which does not equal a photon of energy 3ev
What is ionisation?
It is when an atom gains or loses an electron and become charged
What is excitation?
It is when an electron moves up an energy level by absorbing a photon with the exact right amount of energy or absorbing energy when colliding with free electrons
What is line spectra?
It is a spectrum of discrete coloured lines.
What is continuous spectra?
It is a spectrum where all frequencies of radiation colours of light are possible
What is the emission spectrum?
It is a bright spectrum seen when electrons are emitted
What is the absorption spectrum?
It is a spectrum of dark lines seen on a coloured background produced when a gas absorbes photons
what is the equation for calculating the frequency of a photon emitted when an electron falls to a lower level?
E2-E1 = hf
What is plasma?
It is the mixture of ions and electrons in a gas.
