Changes

[[Image:lighterstill.jpg]]

[[Image:lighterstill.jpg]]

[[Image:Helium_atom_QM.svg.png|right|frame|<center>This illustrates the [http://en.wikipedia.org/wiki/Nucleus nucleus] (pink) and the [http://en.wikipedia.org/wiki/Electron_cloud electron cloud] distribution (black) of the [http://en.wikipedia.org/wiki/Helium Helium] atom. The nucleus (upper right) is in reality spherically symmetric, although this is not always the case for more complicated nuclei</center>.]]

[[Image:Helium_atom_QM200.jpg|right|frame|<center>This illustrates the [http://en.wikipedia.org/wiki/Nucleus nucleus] (pink) and the [http://en.wikipedia.org/wiki/Electron_cloud electron cloud] distribution (black) of the [http://en.wikipedia.org/wiki/Helium Helium] atom. The nucleus (upper right) is in reality spherically symmetric, although this is not always the case for more complicated nuclei.</center>]]

==Origin==

==Origin==