What do the two dots mean, for example, the "Ö" in Wikipedia.org - Hydroxonium-cation.svg

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    $\begingroup$ 30 characters limit is the system feature against the users who do not bother with topic research before asking nor with the question elaboration. Such questions are almost universally closed as Homework with lack of effort or a post with lack of details. Answering them would increase redundancy of internet. // Review the guide How to ask and Asking FAQs to prevent clarification requests, objections, down-voting or closure. $\endgroup$
    – Poutnik
    Commented Sep 26, 2023 at 8:21
  • $\begingroup$ Please provide more details. Otherwise, it will be closed as Homework. $\endgroup$ Commented Sep 26, 2023 at 10:04
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    $\begingroup$ Well, it ain't an umlaut... $\endgroup$ Commented Sep 26, 2023 at 13:09
  • $\begingroup$ @Mithoron My answer is terse for a reason ... $\endgroup$
    – Ian Bush
    Commented Sep 26, 2023 at 14:17
  • $\begingroup$ @IanBush I was rather intending to criticise the question, than answer. Your post is fine for it, but should be rather a comment. I don't imagine we're gonna keep this q. too long. $\endgroup$
    – Mithoron
    Commented Sep 26, 2023 at 15:16

1 Answer 1


It represents a lone pair of electrons in a Lewis Structure.


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