So I am completely and utterly confused about why sulfur has 12 valence electrons. I understand in it's configuration, it has 2 electrons for the 3s subshell, and 4 electrons from its 3p subshell, and it can use the 3d subshell since its in period 3. Therefore it is able to exceed the octet, and form more than just 4 covalent bonds.
But how exactly do you calculate the exact number of "12 electrons" in the valence electron, which thus allows it to participate in 6 covalent bonds with oxygen in the sulfate ion, SO4-2? I can't seem to understand :(
Thanks so much!