What are the key differences between raw tin and the tin used for soldering electronic components?
Tin is a Tin, a chemical element #50 "Sn", a metal. Obviously the metal can't be 100% chemically pure, and only can be supplied with with certain level of impurities, likely different in different products, which should be specified by manufacturer. So, there is no "raw tin" without corresponding purity certificate.
For soldering electronic components, I know of only one 100% Sn solder, Indalloy Number 128. If you provide the datasheet for what you call "raw tin", then the metals can be compared.
For hundreds of other soldering alloys there is a good source to learn, Indium Corporation .