Why is gas chromatography used over paper chromatography, what can gas chromatography do that paper chromatography cant?

Which phase does the carrier gas represent?

Why use a syringe to deliver your samples?

Why is gas chromatography heated in an oven?

What is 'retention time'?

Paper chromatography also called TLC (Thin Layer Chromatography) is commonly using for separating and identifying liquid mixtures that are or can be coloured, especially pigments.

The GC (gas chromatography) is much faster because everything happens in gas phase = atoms & particles moving much faster. And this is one of the reasons why we heated in an oven. The second reason why we heat: we must have gas phase without any liquids, etc ... and the third reason: the higer temperature gives the shorter retention time and the shorter time of whole analysis.

Another advantage of GC is flexibility ... we can evaporate a lot of liquids or solids to gas phase, in proper temperature of course (see above). So we can analyze a lot of chemicals ...

We use a syringe because we should deliver only very small portion of measuring substance, because this is preventing to overload and pollute analytical column filled by stationary phase. If you pollute that column = you can just throw away because will be useless.

The carrier gas represent a moving phase - its carrying our sample through the analytical columns.

I think, you should look at wikipedia: 'Gas Chromatography'.