I am currently working on noble gas configurations in chemistry and I am having a hard time understanding why I got two questions wrong on a practice.

The instructions for the practice are here:

Write out the noble gas configuration for the element. Enter your answer with all values without any spaces, hyper scripts or subscripts

Example: Sulfur S - $\ce{[Ne] 3s^2 3p^4}$ --> [Ne]3s23p4

My questions are:

  1. Write the noble gas configuration for Zr:

  2. Write the noble gas configuration for Ho:

My answers were:

  1. $\ce{[Kr] 5s^2 4p^6 4d^2}$ --> [Kr]5s24p64d2

  2. $\ce{[Xe] 6s^2 5p^6 4f^{11}}$ --> [Xe]6s25p64f11

I am still getting the answers wrong. Where did I go wrong in my configurations?

  • $\begingroup$ Check the prefixes for s and p orbitals. $\endgroup$
    – Poutnik
    Oct 15 '20 at 19:29
  • $\begingroup$ What does that mean? Can you show me what that looks like? Are my letters not in the correct order? $\endgroup$
    – Audrey W.
    Oct 15 '20 at 19:32
  • $\begingroup$ 4p is part of [Kr], so does 5p of [Xe]. Check the periodic table. $\endgroup$
    – Poutnik
    Oct 15 '20 at 19:39
  • $\begingroup$ I'm still not understanding. $\endgroup$
    – Audrey W.
    Oct 15 '20 at 19:42
  • 1
    $\begingroup$ "noble gas configuration for zirconium" is a terrible slang to be taken "configuration of zirconium written using the previous nearest noble gas and adding the remaining electrons". $\endgroup$
    – Alchimista
    Oct 16 '20 at 11:43

Zirconium is $\ce{[Kr] 4d^2 5s^2}$. Holmium is $\ce{[Xe] 4f^{11} 6s^2}$. But they don't have the configuration of a rare gas.

  • $\begingroup$ Is this the answer? $\endgroup$
    – Audrey W.
    Oct 15 '20 at 21:17
  • 1
    $\begingroup$ @AudreyW.- No that is not correct. Zirconium is $\ce{[Kr] 4d^2 5s^2}$ $\endgroup$
    – MaxW
    Oct 15 '20 at 23:08
  • $\begingroup$ @ MaxW. Thank you. My mistake was ridiculous. $\endgroup$
    – Maurice
    Oct 16 '20 at 7:11

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