# Should chemical compounds and elements be capitalized?

In the case of a name of a person, the first letter is written in capital letters.

• Should the first letter of name of a chemical compound or element be written in capital letters?
• – Loong Jan 22 '17 at 21:20

The names of chemical compounds and elements should be capitalized if they appear at the beginning of a sentence or in a title - that is, they are treated just like any other common noun.

For example, a title:

Why I Don't Like Zinc

or a sentence:

Boron is my favorite element.

Within a sentence:

We used boron and zinc in the experiment.

Vinegar contains acetic acid.

The symbols for chemical elements are always capitalized, no matter what:

We combined $\ce{As}$ and $\ce{W}$ to make a new alloy.

• In the 1979 and 1993 IUPAC recommendations, example names were actually written with a capital initial letter. This was not necessarily wrong since most examples started on a new line. However, this practice has been abandoned in the 2013 recommendations in order to ensure that names of organic compounds are not considered as proper nouns. – Loong Jan 22 '17 at 21:40
• Capitalising (some) words in a title is a matter of taste, not orthography. – Karl Jan 22 '17 at 22:28
• @Karl That's like saying "Whether it's 'colour' or 'color' is a matter of taste, not spelling." Capitalization is literally orthography: the way things are written down. – David Richerby Jan 22 '17 at 23:55
• @ToddMinehardt i.e. glucosamine (N-acetyl)-6-sulfatase – Another.Chemist Jan 23 '17 at 19:30
• "N" is an element symbol, always uppercase. – Karl Jan 23 '17 at 19:40

One addition to Todd's correct answer is that of trade names. The canonical example of Teflon being capitalized, the name being property of DuPont. https://en.m.wikipedia.org/wiki/Polytetrafluoroethylene

Although Teflon is not the chemical name, the distinction is added to avoid possible confusion.

• And complicated cases, such as acetylsalicylic acid, which is "Aspirin" in countries such as Canada, where Beyer holds a trademark, and "aspirin" in countries such as the US and UK, where the trademark lapsed and it's now considered to be a nonsystematic name. – David Richerby Jan 23 '17 at 12:21