中四化學電子圖問題

CaSO4的畫法如下圖所示:

圖片參考：http://imgcld.yimg.com/8/n/HA00950331/o/701010020041813873374890.jpg

圖片參考：http://imgcld.yimg.com/8/n/HA00075708/o/701010020041813873374880.jpg


I don't agree with 001's answer. reasons are:
1. it missed the electrical charge of ions. calcium ion possesses 2+ charge, while sulphate ion possesses 2- charge.

2. calcium did not donate any electrons to sulphate ion. please imagine before combining into solid calcium sulphate, what happens to sulphate ion.

when sulphuric acid is dissolved in water, it ionizes to give hydrogen ions and sulphate ions ---- without any calcium. clearly electrons on sulphate cannot belong to calcium. actually those two electrons are originally possessed by sulphate ion, and are kept in their original place even after formation of calcium sulphate. NO electron transfer between calcium and sulphate, please.

in diagram above, red dots represent electrons of oxygen, blue ones belong to sulphur. replace one kind of them by cross will do.
if you want, you can also draw 8 electrons surrounding calcium, representing the full outermost (third) electron shell.

you can also notice that sulphur possesses more than 8 electron -- it has 12. this violates octet rule, but is "special case" in your sense -- that's very normal, especially for the oxygen-containing ions.