Draw the shape of an SF6 and SF4 molecule, indicating bond angles and any lone pairs which may influence these. What shape is the SF6 molecule?

Sulfur is a group six element, meaning it can form up to six bonds with halogen atoms such as F or Cl. In the instance where only four valence electrons of S are bonded to the halogens, the remaining two electrons will form a 'lone pair'. Lone pairs and chemical bonds are both regions of high electron density, meaning each is capable of repelling the other and influencing the shape of sulfur fluorides molecules. In the case of SF6, all six of the S-F bonds are at maximum and equal distances from eachother, such that each is at right angles to its neighbours. The resulting shape is referred to as being octahedral, since if one were to draw lines between each of the F atoms, a regular eight-faced shape would result (this is easier to demonstrate on the whiteboard). In SF4, the situation is a little more complicated; however, if we make the simplification that the lone pair repels the S-F bonds equally as strongly as they repel eachother, we can approximate a trigonal bipyramidal shape. In reality, we know that the lone pair is more strongly repellent as the electron density is not spread out between two bonding atoms, so all of the bonding angles are slightly compressed such that the angles are slightly below 90, 120 and 180 degrees (again, easier to demonstrate with the whiteboard!).