Turn on thread page Beta
    • Thread Starter
    Offline

    5
    ReputationRep:
    I was given an exam question concerning election configurations and after checking the mark scheme i found it said that the answer that i gave was to be rejected.

    The question asked me to fill to complete the electron configuration of a copper atom
    they complete the electron configuration up to  3_p
    My answer was  3d^94s^2, the mark scheme gave the answer 3d^1^04s^1 is 4s filled first.
    Offline

    10
    ReputationRep:
    Yes, in Copper and Chromium (the two exceptions) the 4s is filled in first. This is when, in chromium it ends in 3d54s1. I think, this is what i remember.

    This is due to it being more stable when there are 5 pairs of electrons in the 3d orbital, as opposed to 4 pairs and an odd one.
    Offline

    19
    ReputationRep:
    (Original post by Thomas...)
    Yes, in Copper and Chromium (the two exceptions) the 4s is filled in first.
    The two you need to know about for A level, that is.
    Offline

    10
    ReputationRep:
    (Original post by BJack)
    The two you need to know about for A level, that is.
    Ok ok ok. I have been out-shone.
    Ha, I was just regurgitating what I remember from last year! Thanks for the edit.
    • Thread Starter
    Offline

    5
    ReputationRep:
    (Original post by Thomas...)
    Yes, in Copper and Chromium (the two exceptions) the 4s is filled in first. This is when, in chromium it ends in 3d54s1. I think, this is what i remember.

    This is due to it being more stable when there are 5 pairs of electrons in the 3d orbital, as opposed to 4 pairs and an odd one.
    Right i see thank you very much for your help
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: April 8, 2011
The home of Results and Clearing

2,867

people online now

1,567,000

students helped last year

University open days

  1. SAE Institute
    Animation, Audio, Film, Games, Music, Business, Web Further education
    Thu, 16 Aug '18
  2. Bournemouth University
    Clearing Open Day Undergraduate
    Fri, 17 Aug '18
  3. University of Bolton
    Undergraduate Open Day Undergraduate
    Fri, 17 Aug '18
Poll
Do you want your parents to be with you when you collect your A-level results?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.