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.
Valence electrons are the electrons present in the outermost shell of an atom. You can easily determine the number of valence electrons an atom can have by looking at its Group in the periodic table. For example, atoms in Groups 1 and 2 have 1 and 2 valence electrons, respectively. Atoms in Groups 13 and 18 have 3 and 8 valence electrons, respectively. Valence electrons are responsible for the reactivity of an element. They determine how willing the elements are to bond with each other to form new compounds. If the valence shell of an element is full, such as with a noble gas, then the element does not want to gain or lose an electron.