Lewis Dot of Sulfur Hexafluoride
SF6 is a colorless odorless, nontoxic and nonflammable gas. It has a density of 6.1g/L (at sea level), which is a very dense gas. When inhaled it has the opposite effect that helium would have. Remember helium is not dense at all. Here is are 3 videos.
S does not follow the octet rule. It will hold more than 8 electrons.
Sulfur having valence electrons in the 3rd energy level, will also have access to the 3d sublevel, thus allowing for more than 8 electrons.
Elements in the first 2 periods of the Periodic Table do not have access to the d sublevel and must adhere to the octet (or duet H and He) rule.