Why are teachers now saying electrons are in orbitals? I thought they moved around shells?

Unfortunately, every year in school you are told that something from the previous year was not completely true, and had in fact been simplified...one of the major examples of this is orbitals. While the electrons are in shells, these shells are made up of 'sub shells' known as orbitals, which can each hold 2 electrons. At A Level there are 3 types of orbital you need to know: S, P and D, and you need to try and see these in 3D to understand them fully. Using model kits, good drawings or websites such as chemtube3d.com can be very helpful for this. But there is no need to worry, because the periodic table is split up into 'blocks' which make seeing which electrons are in which orbital much easier.