2.2 Electron configuration Flashcards
How are electrons arranged in an atom?
in energy levels (shells) around the nucleus
Which energy shell has the lowest energy level?
The first shell
What happens to the energy of the shells as they get further away from the nucleus
The shells increase in energy
What is the general rule for filling energy shells? (up to elements with atomic number 20)
1) electrons fill them out from lower energy to highest (nucleus out)
2) the first two energy levels must be completely filled before an electron goes into the next energy level
3) The third main energy level is only filled to 8 before electrons are put into the fourth main energy level
what are particles of electromagnetic radiation?
Photons
Where is there evidence for energy levels in atoms?
The hydrogen atom spectrum
what is it called when light is emitted by the gas?
an emission spectrum
What is a line spectrum?
spectrum consisting of a series of sharp, bright lines on a dark background. Only certain frequencies/wavelengths of light are present
What is a continuous spectrum?
spectrum consisting of all the colours merging into one another.
How is an emission formed?
1) pass an electric current through a gas
2) this causes an electron to be promoted to a higher energy level
3) the electron is unstable in this higher level so will fall to a lower energy level
4) As it returns to the normal energy level, extra energy is given out in the form of a photon of light which contributes to the line in the spectrum
Where do the lines in the spectrum come from?
Each line in the spectrum comes from the transition of an electron from a high energy level to a lower one
How many energy levels are there?
5
Why do different series of lines occur?
When electrons fall back down to different energy levels
Between which levels is there the biggest energy difference?
level 1 (ultraviolet) and 2 (Visible)
