How to determine electron configuration with just a periodic table?

How would I find the electron configuration of an element using the periodic table?



Can you give me an example using I/iodine please?How to determine electron configuration with just a periodic table?
Alright. So you have your periodic table. If you look at the element, then in the bottom right corner of the element's box, you should see some numbers (not all periodic tables have this). If the numbers were 2-4-4 that would mean there are 2 electrons In the first shell, 4 in the second and 4 in the third. Sorry, I can't do an example cause i can't find a table with electron config.How to determine electron configuration with just a periodic table?
The ability to find out the electron configuration of an atom in the periodic table depends on the periodic table used. There are several variants.



If you are referring to the common one, then you must know that in the first period, the first shell can only contain 2 electrons. The shells in the second period can hold 8 electrons. The third shell, according to the period as that period has 8 elements, can hold 8 electrons, though I'm not too sure about that. The fourth shell can hold 18 electrons as the fourth period has 18 elements, and so does the fifth period. Since Iodine is in the fifth period and the 7th group, its electron configuration should be 2.8.8.18.17



NB I'm not too sure, because this is not a very accurate way. Because of the transition metals, the lathanides and the actinides, the electron configuration are much different, and this would change the electron configuration of other elements. You might want to check and do a little bit of research first.
Iodine is large, but as you can see it falls in the same column as all other halogens, F%26lt;CL%26lt;BR%26lt;I, etc, which means it is 1 electron short from its happy less reacted state, anion, cation etc. so yo could go

H = 1s one electron

He = 1s2 two electron

Li = 1s22s1 three electron.

F = 1s2,2s2,2p6, etc

Mg = 1s2, 2s2, 2p6, 3s2 ie, 3rd row, hence 3, column 2.

iodine goes form say all the wayfrom 1s2..to 4s2, 3d1-10,4p5

google this and what 2bob has said, will be more clear.



ie, neutral elements, protons = electrons, generally netrons sum up the by atomic number - ( nu of elecron + proton) will give you the number of neutrons, there are numerous isotopes, but the atomic number are an average number. basically the periodic table gives you so much, and is VERY IMPORTANT to get your head around, if chem is your thing.
Ok well the reference table given to me by my teacher is the 2002 edition. But anyways lets proceed to find the electron configuration of Iodine.

1. First off, if you have the same reference table as me, go to page 11( the last page).



2. It should say 'Properties of Selected Elements'. This table may be on a diff page in your reference table.



3.Find Iodine and it should say that the atomic number for it is 53. Knowing the atomic number tell us how many electrons and protons there are. The number of protons and electrons in a atom are always the same, despite the electron having no definite charge.



4. Now that we know the number of electrons is 53 we proceed to writing the configuration. we have to write it in such a way that it adds up to 53. This is the order we must follow: 1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s2, 4p6, 4d10, 4f14.



5. The electron configuration for Iodine is: 1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s2, 4p6, 4d10, 4f7.



6. If you add 2 plus 2 plus 6 plus 2 plus 6 plus 10 plus 2 plus 6 plus 10 plus 7 it equals to 53. In the order in step 4the last step was '4f14' However, if we put that in the configuration the numbers would add up to 60. And thats beyond 53. So we have to stop at 53 even if it means reducing the '10' in 'f10' to a '7'. Number of unpaired electrons is 0.