Formal charge: kind of confused?

Question

why cant i get -1? i just want to know if the way im solving it, if its completely wrong. i have a test soon. please help!

tinypic
. com
/view.php?pic=14buuti&s=7

ok in class we did this.
and for O FC= 6-4-3=+1
but S FC = -1 (I get 6-4-1= +1) which is wrong. what am i doing wrong?

i solve by doing: group # - total (bonds and lone pairs(each = 1)) - lone pairs (each pair = 1)

Answer 1

Sorry but that url doesn't help me. I get nothing although I do get a tiny pic page.

I don't use this "formula" method because it takes me longer to classify group #, bonds, and lone pairs than to count. Here is how you can count them.
http://www.google.com/images?q=lewis+structure+SO2&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&source=univ&ei=GjlYTe65GsT0gAeGrL2EDQ&sa=X&oi=image_result_group&ct=title&resnum=2&ved=0CCsQsAQwAQ&biw=791&bih=398

Count electrons around an atom as follows:
1 each for unshared electrons. Electrons shared between atoms--give half of the electrons in the bond to each atom. The formal charge is then What it should have - what it has. For H2O,
&nbsp ..
H:O:
..
H
So H has 1 electon, it should have 1, FC = 0
Other H is the same.
O. We have 2 electrons at the top and two on the right side (total now 4) + 1 electron for 1 H -O bond and 1 for the other H-O bond which makes 6. It should have 6. FC = 0