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Take monosodium glutamate. Its chemical formula is $$\ce{C5H8NO4Na or C5H8NNaO4}$$ First way nitrogen, oxygen, sodium, with is in order of element's name. Second way, N, Na, O, in order of element's symbol. Have seen it both ways, hoping someone could clarify. Thanks.

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marked as duplicate by Jan, Todd Minehardt, Klaus-Dieter Warzecha, NotEvans., Jon Custer Aug 27 '16 at 12:17

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    $\begingroup$ Organic Chemists have a bias for C, H, N and O, so by habit I tend to write those ones first. I don't actually know the formal rule. $\endgroup$ – Lighthart Aug 25 '16 at 15:37
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Go straight to the original source, ON A SYSTEM OF INDEXING CHEMICAL LITERATURE; ADOPTED BY THE CLASSIFICATION DIVISION OF THE U. S. PATENT OFFICE, and you can see that Hill uses the element symbol to determine alphabetical order.

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In your example $\ce{C5H8NNaO4}$ is correct.

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    $\begingroup$ The current IUPAC Red Book (2005) also refers to the original Hill publication. However, IUPAC recommends the order ‘B before C’ for carbaboranes as an exception to the Hill order. $\endgroup$ – Loong Aug 25 '16 at 16:00

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