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Iodine configuration help ?!?!?!?

So.. What is the configuration of iodine?

I thought it was 2,8,8,8,8,8,8,3 because that adds up to 53.. But in one of rhe GCSE questions it says in the outer shell iodine has 7 electrons.. So how does that work?
Original post by tamanna___
So.. What is the configuration of iodine?

I thought it was 2,8,8,8,8,8,8,3 because that adds up to 53.. But in one of rhe GCSE questions it says in the outer shell iodine has 7 electrons.. So how does that work?


You are never expected to go past Calcium when writing the electron configuration of elements. You will learn at A-Level there are s,p,d and f orbitals, s containing 2 electrons, p containing 6, d containing 10, and f containing 14. So in fact the electronic configuration of Iodine would be
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d 10 5s2 5p5 <---- 5s2 and 5p5 =7.
2.8.18.18.7
Reply 2
Original post by Billy_Boi
You are never expected to go past Calcium when writing the electron configuration of elements. You will learn at A-Level there are s,p,d and f orbitals, s containing 2 electrons, p containing 6, d containing 10, and f containing 14. So in fact the electronic configuration of Iodine would be
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d 10 5s2 5p5 <---- 5s2 and 5p5 =7.
2.8.18.18.7



Well the question was in the january 2013 paper so ill just learn it to be on the safe side.. And why does it change to 18?? Ive always learnt the maximum in the outer shell is like 2,8,8,8,8 etc
Original post by tamanna___
Well the question was in the january 2013 paper so ill just learn it to be on the safe side.. And why does it change to 18?? Ive always learnt the maximum in the outer shell is like 2,8,8,8,8 etc


Wow seriously? What exam board is this? Well it goes 2,8,8,18 etc... so after the 3rd shell it goes from 8-18 as there are more orbitals meaning more electrons can fit in. Just remember that and you'll be fine.
Reply 4
Original post by Billy_Boi
Wow seriously? What exam board is this? Well it goes 2,8,8,18 etc... so after the 3rd shell it goes from 8-18 as there are more orbitals meaning more electrons can fit in. Just remember that and you'll be fine.


AQA and omg this is so confusing.... Wow ok it turns to 18 from the 3rd shell... This is all new to me woah
Original post by tamanna___
AQA and omg this is so confusing.... Wow ok it turns to 18 from the 3rd shell... This is all new to me woah


No, sorry if I was unclear AFTER the 3rd shell, so 4th onwards. Could you send me a link to this paper? I did AQA as well and never needed to know any of this.
Reply 6
Original post by Billy_Boi
No, sorry if I was unclear AFTER the 3rd shell, so 4th onwards. Could you send me a link to this paper? I did AQA as well and never needed to know any of this.


http://filestore.aqa.org.uk/subjects/AQA-CH2HP-QP-JAN13.PDF

Question 5 (c i)

Its only one question but you would still need to know this info in order to get the correct answer
Original post by tamanna___
http://filestore.aqa.org.uk/subjects/AQA-CH2HP-QP-JAN13.PDF

Question 5 (c i)

Its only one question but you would still need to know this info in order to get the correct answer


I see, but just a rule of thumb to remember is that Group 1 metals have 1 electron in their outer shell, G2 has 2, G3 has 3, etc... So you would look at your periodic table that you are provided and see Iodine is in G7 and use that prior knowledge to say there are 7 electrons in Iodine's outer shell.

Hoped this helped.
Original post by Billy_Boi
No, sorry if I was unclear AFTER the 3rd shell, so 4th onwards. Could you send me a link to this paper? I did AQA as well and never needed to know any of this.


Well that's not strictly true is it, the 3d electrons are part of the 3rd shell.
Original post by tamanna___
So.. What is the configuration of iodine?

I thought it was 2,8,8,8,8,8,8,3 because that adds up to 53.. But in one of rhe GCSE questions it says in the outer shell iodine has 7 electrons.. So how does that work?


As someone above has already said, number of outer shell electrons is same as group number. Iodine is group 7 so has 7 outer shell electrons. There is no need to go any further than this at GCSE.

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