Dimethylmercury ((CH3)2Hg) is an organomercury compound. This colorless liquid is one of the strongest known neurotoxins. It is described as having a slightly sweet smell, although inhaling enough vapor to detect its odor would be hazardous.
The formation of a star begins with gravitational instability within a molecular cloud, caused by regions of higher density-often triggered by shock-waves from nearby supernovae (massive stellar explosions), the collision of different molecular clouds, or the collision of galaxies (as in a starburst galaxy).
Van der Waals forces. Electrons in charge clouds move. At any moment the electrons in an atom are likely o be more to one side. At this movement the atom has a temporary dipole. This can cause another induced dipole in the opposite direction. The two dipoles are then attracted to each other.