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Chemistry

An element has the electronic configuration
1s2,2s2,2p6,3s2,3p6,3d10,4s2,4p6,4d10,5s2,5p6.
i) Which group does it belong to ?
ii) Identify the element
i) The group number is equal to the number of outermost electrons.
For example, 1s2 2s2 2p6
The outermost shell is the 2nd energy shell. It is made up of 2 sub-shells which are 2s and 2p.There are therefore 8 electrons in the outermost shell. Therefore the element is in group 8/0.

ii) The total number of electrons can be calculated by adding all the numbers following s p d and f
for example, 1s2 2s2 - there are (2 + 2=) 4 electrons. This means the atomic number is 4 and therefore the element is Beryllium)

It's quite hard to explain in text but I hope that helped somewhat. I'd also suggest you watch the freesciencelessons video on this:
https://www.youtube.com/watch?v=6jKTbT81jY8&list=PL9IouNCPbCxXqcP3rJvu4_IqOf1Z_fWDJ&index=1
(edited 1 year ago)
Original post by egyankortheone
An element has the electronic configuration
1s2,2s2,2p6,3s2,3p6,3d10,4s2,4p6,4d10,5s2,5p6.
i) Which group does it belong to ?
ii) Identify the element

I suppose to that the nunbers in bold print are in superscript? if so, you have the numbers of electrons in an orbital then. All these electrons added results in the total number of electrons and thus the atomic number. The rest should be a piece of cake.

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