based on the stawa book lol

experiment 9: emission spectra

spectroscopy works on the principle that substances absorb energy and emit energy as EMR (electromagnetic radiation).
the radiation is absorbed or emitted in bundles (protons). what is a bundle lmao
- radiation frequency wavelength corresponds to colours, and is specific to the atoms that make up the substance.
when an element is heated the electrons in their ground state absorb energy and move to higher energy levels.
when they return to lower energy levels, energy is emitted as light.
- light can be seen as distinct colours.

procedure

the substance is vaporised, and put into a discharge tube.
an electric discharge is passed through the tube. electrons in the discharge excite other electrons by transferring kinetic energy during collision, then deflecting and losing energy.
the electrons are excited to a higher energy state (as it has experience an increase in energy exactly equal to E2-E1)
since they are unstable in their excited state, they will transition down to their ground state, and release energy in the form of radiation that has energy exactly equal to E2 - E1.
since multiple transitions can occur within an atom, a unique set of photons with a specific wavelength each is produced; thus when these emissions are captured and analysed in a line spectrometer; we only see specific light present.
this produces a single stream of radiation, as all the wavelengths are travelling in the same direction, being combined together.
when the radiation is passed through a prism, the different frequencies/wavelengths are separated from each other, and are projected onto a black spectrum.
it takes the form of coloured lines on a black background.
because all elements have a unique spectra, we can identify the elements based on this.