The shortcuts for Windows 7. If you have not made the leap to Windows 8, this little cheat sheet will help you work more efficiently with Windows 7. Note: This list is part of Greg Shultz's comprehensive collection of Windows keyboard shortcuts, available as a PDF download. Also read: Free cheat sheet of 100 Windows 8 keyboard shortcuts.
i just ran across a problem asking me to identify the valence electrons on a sulfur atom in a sulfate ion. my understanding is that sulfate ion = 4 oxygen + 1 sulfur atom and has a 2- charge. now, in the answer to this question, it reads: sulfur in a sulfate ion has 12 valence electrons, its original six... *which i was able to find; 1s2,2s2,2p6,3s2,3p4 plus 6 more from the oxygens to which it is bonded.
S can form up to 6 bonds with oxygen in the compound SO3. That is, three double bonds. Look up expansion of the valency octet. The S atom has 12 electrons in its outer level in SO3. because sulfur is larger than oxygen, it does have the ability to expand its valence shell and form more than two bonds. In other words, the Octet Rule only really works for the smaller atoms, and is easily violated on larger ones. For example, in H2SO4, the sulfur atoms is bonded to 4 O atoms.