posted by Chemistry .
Write the electron configuration of Sn and Sn2+
Give the electron configuration of Cu+ and Cu2+
Same response as before. If you still have a question, explain what it is that you don't undrestand.
What I don't understand is where I get the number of dots from and what is the electron configuration
You get the number of dots from the periodic table. For example, Na is Na. and Ba is Ba: (because Na is in group I and has 1 electrons in its outside shell and Ba is in group II and has 2 electrons in its outside shell). Cl is in group VII (or 17 depending upon which system you are using) and has 7 electrons in its outside shell.
The electron configuration is done following two rules.
2 s electrons, 6 p electrons, 10 d electrons, and 14 f electrons. The ORDER of filling is
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 which will get you through element 38. There are two exceptions in this chain; one is Cr and the other is Cu. The ground state of both Cr and Cu have 1 fewer electron in the 4s and 1 more electron in the 3d than the above scheme provides. Let me know if you still have questions about this but please be specific.