Collisions of electrons with Atoms Flashcards
1
Q
What are electrons in atoms arranged in
A
discrete energy levels
2
Q
How do electrons in atoms gain energy
A
collision with free electron
3
Q
If electron in atom gains energy what happens
A
excites and moves up in energy level
4
Q
If electron in atom gains more than ionisation energy what happens
A
removed from atom entirely
5
Q
What happens after electron excitation
A
electron quickly returns to ground state level
releasing energy gained as a photon
6
Q
What is the concept of a fluorescent lamp
A
voltage fires free electrons through tube of mercury vapour
free electrons collide with mercury atoms causing ionisation
causes excitation and release of UV light
fluorescent coating absorbs UV photons and electron in the coating excite and de-excite releasing white light
