Electrons and Energy levels Flashcards
What is the equation for photon energy?
E = hf
What is an electron volt?
The kinetic energy gained/lost from an electron accelerated through a potential difference of 1 volt
What is the ground state of an electron?
The lowest energy state in an atom
What is excitation?
When an electron moves to a higher energy level after absorbing energy
What can cause an electron to be excited?
- absorbing a photon with the exact energy needed
- absorbing the exact energy needed after colliding with a free electron that has energy >= the energy required
When does ionisation occur?
When an atom gains or loses an electron and becomes a charged particle called an ion
What is ionisation energy?
The minimum energy needed to remove an electron from an atom completely
What happens when an electron drops to a lower energy level?
It emmits a photon and moves closer to the nucleus
What are continuous spectra?
A spectrum where all frequencies of radiation are possible
What is a line spectrum?
A spectrum of discrete coloured lines of light
What is an emission spectrum?
A bright spectrum seen when photons are emmited by atoms
Absorbtion spectrum
Is a spectrum of dark lines seen on a coloured background produced when a gas absorbs photons
How do absorbtion spectra form?
When light shines through a gas, electrons in an atom absorb photons corrisponding to their energy level. All other photons pass through
What are fraunhofer lines?
The continuous spectrum from the sun is overlayed with 570 absorbtion lines
