chemistry - atomic models

emission spectrum

• light runs through gas then gas glows and emits light then light is separated by prism

• coloured bands show which wavelength of photons were emitted

absorption spectrum

• gas absorbs specific wavelenghts of white light that passes through it

• dark bands show which wavelengths of photons absorbed

what happens when electrons absorb light

• gain energy

• electrons move to a higher energy level, becoming excited

• when the relesease energy they return to their lower energy level

aufbau principle

electrons always fill lower energy subs shells first

hunds rule

spread electrons through degenerate orbitals before pairing them

pauli exclusion principle

orbitals can only hold 2 electrons with opposite spins