"a" or "an" before chemical symbols

[Stewart Gordon]

In scientific papers and reports, it's common to use the chemical symbol
of an element in a sentence or heading, rather than writing out the name
of the element in full.

However, I can't seem to make up my mind which form of the indefinite
article should precede such a symbol.

I suppose it depends on the implied pronunciation of the symbol in the
context of the sentence. I suppose that when reading it aloud, one is
likely to replace the symbol with the element name, but I'm not sure if
that answers the question.

Some cases are ambiguous, e.g. C begins with a consonant, and Al begins
with a vowel, however you read it. But otherwise, there are three
possibilities I can see:

a Fe atom, an Au atom (a fee atom, an au atom*)
an Fe atom, an Au atom (an eff-ee atom, an ay-ewe atom)
an Fe atom, a Au atom (an iron atom, a gold atom)

*This is before you get to the two-consonant symbols, which naturally
aren't so easy to pronounce....

Is any of these the preferred way of doing it?

Stewart.

--
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My e-mail is valid but not my primary mailbox. Please keep replies on
the 'group where everyone may benefit.

[Stewart Gordon]

[Made a typo the first time. Don't know if my cancel request worked....]

In scientific papers and reports, it's common to use the chemical symbol
of an element in a sentence or heading, rather than writing out the name
of the element in full.

However, I can't seem to make up my mind which form of the indefinite
article should precede such a symbol.

I suppose it depends on the implied pronunciation of the symbol in the
context of the sentence. I suppose that when reading it aloud, one is
likely to replace the symbol with the element name, but I'm not sure if
that answers the question.

Some cases are unambiguous, e.g. C begins with a consonant, and Al

[Ray Heindl]

Stewart Gordon <smjg...@yahoo.com> wrote:

[snip]

> Some cases are unambiguous, e.g. C begins with a consonant, and Al
> begins with a vowel, however you read it. But otherwise, there
> are three possibilities I can see:
>
> a Fe atom, an Au atom (a fee atom, an au atom*)
> an Fe atom, an Au atom (an eff-ee atom, an ay-ewe atom)
> an Fe atom, a Au atom (an iron atom, a gold atom)
>
> *This is before you get to the two-consonant symbols, which
> naturally aren't so easy to pronounce....
>
> Is any of these the preferred way of doing it?

Just my two Cu cents, probably not worth a plugged Ni:

If you use the symbol you should expect it to be pronounced as one or
two letters (i.e. Fe = "eff ee", not "iron" or "fee"), and use "a" or
"an" as appropriate to the first letter. Thus the two-consonant
symbols are no different from the others. If you want the full name
used, spell it out.

I've never heard "fee" for Fe or "awe" for Au; does anyone really
pronounce symbols that way?

--
Ray Heindl
(remove the Xs to reply)

[Don Phillipson]

"Stewart Gordon" <smjg...@yahoo.com> wrote in message
news:drl9ho$rl8$3...@sun-cc204.lut.ac.uk...

> a Fe atom, an Au atom (a fee atom, an au atom*)
> an Fe atom, an Au atom (an eff-ee atom, an ay-ewe atom)
> an Fe atom, a Au atom (an iron atom, a gold atom)
>
> *This is before you get to the two-consonant symbols, which naturally
> aren't so easy to pronounce....
>
> Is any of these the preferred way of doing it?

Case 2 is correct, i.e. we say and we write AN
before Fe and Au ("eff ee" and"ay you"). The
reason is the way we pronounce initials F and A,
with a vowel first.

--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)

[Mark Brader]

Stewart Gordon:

> > a Fe atom, an Au atom (a fee atom, an au atom*)
> > an Fe atom, an Au atom (an eff-ee atom, an ay-ewe atom)
> > an Fe atom, a Au atom (an iron atom, a gold atom)

Don Phillipson:

> Case 2 is correct, i.e. we say and we write AN
> before Fe and Au ("eff ee" and"ay you").

Case 2 *would* be correct *if* we pronounced it "an eff ee atom".
I don't imagine many people do, unless they're deliberately making
a point about the use of the symbol instead of the word "iron".

I'd use version 3 if I had to, but I'd actually try to look for
another wording first.
--
Mark Brader | "... There are three kinds of death in this world.
Toronto | There's heart death, there's brain death, and
m...@vex.net | there's being off the network." -- Guy Almes

[Paul Wolff]

In message <11u033c...@corp.supernews.com>, Mark Brader
<m...@vex.net> writes

>Stewart Gordon:
>> > a Fe atom, an Au atom (a fee atom, an au atom*)
>> > an Fe atom, an Au atom (an eff-ee atom, an ay-ewe atom)
>> > an Fe atom, a Au atom (an iron atom, a gold atom)
>
>Don Phillipson:
>> Case 2 is correct, i.e. we say and we write AN
>> before Fe and Au ("eff ee" and"ay you").
>
>Case 2 *would* be correct *if* we pronounced it "an eff ee atom".
>I don't imagine many people do, unless they're deliberately making
>a point about the use of the symbol instead of the word "iron".

I'm sure you're right that many people don't ever talk of an Fe atom,
but we chemists do when it seems appropriate. If I was walking you
through a reaction scheme for haemoglobin oxygen transport set out in
diagrammatic form, I'm sure I'd be talking Fe, C, O, H and the like.

Well, pretty sure.

>
>I'd use version 3 if I had to, but I'd actually try to look for
>another wording first.

--
Paul
In bocca al Lupo!

[Wood Avens]

On Wed, 1 Feb 2006 20:05:30 +0000, Paul Wolff
<boun...@two.wolff.co.uk> wrote:

>In message <11u033c...@corp.supernews.com>, Mark Brader
><m...@vex.net> writes
>>Stewart Gordon:
>>> > a Fe atom, an Au atom (a fee atom, an au atom*)
>>> > an Fe atom, an Au atom (an eff-ee atom, an ay-ewe atom)
>>> > an Fe atom, a Au atom (an iron atom, a gold atom)
>>
>>Don Phillipson:
>>> Case 2 is correct, i.e. we say and we write AN
>>> before Fe and Au ("eff ee" and"ay you").
>>
>>Case 2 *would* be correct *if* we pronounced it "an eff ee atom".
>>I don't imagine many people do, unless they're deliberately making
>>a point about the use of the symbol instead of the word "iron".
>
>I'm sure you're right that many people don't ever talk of an Fe atom,
>but we chemists do when it seems appropriate. If I was walking you
>through a reaction scheme for haemoglobin oxygen transport set out in
>diagrammatic form, I'm sure I'd be talking Fe, C, O, H and the like.
>
>Well, pretty sure.

Interesting, because I think I'd expect to read "Fe" as iron -- that
is, I'd mentally translate. In the same way, I'd probably read CO2 as
carbon dioxide, and so on. Hmm. Having written that, I'm not so
sure. I fancy I'd use "KCl" and "potassium chloride" interchangeably,
depending on the context. But I also suspect that single-letter
elements are one thing, and double-letter ones -- Fe, Hg, etc --
another. I can't imagine ever saying either "eff ee" or "fee".

Then again, I'm coming from biophysics rather than chemistry; and
indeed biophysics may have moved on since my time.

--

Katy Jennison

spamtrap: remove the first two letters after the @

[Paul Wolff]

In message <cjc2u1lh4eh663gom...@4ax.com>, Wood Avens
<wood...@askjennison.com> writes

It also helps when one needs, as one does, to distinguish bohrium from
boron while mumbling, or bumps into Du ("Dubnium is a synthetic element
that is not present in the environment at all. It has no uses.")

The tendency to say the symbol rather than the name is limited, as you
suggest. I'd do it when speaking to a graphical representation of what
may be going on. The whole demands research, which I'm not going to
give it. I don't think I'd ever speak of chromium as Cr, but happily
converse on the subjects of SO2 and SO3. Hmm. This is getting dull.
(Checks the ante-post betting - worth one last punt.)

[joeke...@gmail.com]

The American Chemical Society's Style Guide says, when writing, to assume that a chemical formula is going to be read as the chemical name, so that "Au" is read as "gold" and "SiO" is read as "silicon monoxide". So the indefinite article for these two would be "a Au" and "a SiO".

I saw this rule myself in the physical book about ten years ago, and this web page gives the same usage rule with the ACS Style Guide as the reference.

http://www.shearsoneditorial.com/2013/07/a-or-an-with-abbreviations-it-depends/

[Guy Barry]

joeke...@gmail.com wrote in message
news:80ad269d-5681-4a8e...@googlegroups.com...

In what circumstances would you need to use the indefinite article before a
chemical symbol? The examples given in the article are:

' The analyzed DNA is hybridized with a primer nucleic acid that is
associated with a Au surface [pronounced “a gold surface” not “an a-u
surface”].

TGA-DSC measurements were performed under a He flow [pronounced “a helium
flow” not “an h-e flow”]. '

Why would one not write out "gold" or "helium" in full in such contexts?

--
Guy Barry

[Mark Brader]

Guy Barry:

> In what circumstances would you need to use the indefinite article before a
> chemical symbol?

When responding to threads from 2006, it seems.
--
Mark Brader, Toronto "1. Buy 64 more buses."
m...@vex.net --Michael Wares

[Richard Tobin]

In article <BOIXw.241998$ob3....@fx47.am4>,

Guy Barry <guy....@blueyonder.co.uk> wrote:

>In what circumstances would you need to use the indefinite article before a
>chemical symbol?

"A[n] NO3- ion". Of course you could write "nitrate", but I can
imagine cases where the formula would be necessary or preferable, for
example if it didn't have a well-known name or if it had a dummy
symbol in it, e.g. "RNO3".

-- Richard

[Athel Cornish-Bowden]

That's one example among a vast number of similar ones. I'm surprised
the question was asked.

If you accept R as a chemical symbol then the literature abounds with
phrases containing "an R group".



--
athel

[Charles Bishop]

In article <BOIXw.241998$ob3....@fx47.am4>,
"Guy Barry" <guy....@blueyonder.co.uk> wrote:

I certainly would. The chemical symbol in such sentences is an odd use
of them, especially with helium which would cause a hitch in my reading
when I encountered "He" and considered it might be a pronoun.

Perhaps this is true when elements are mentioned, and not when
compounds, such as silicon dioxide, SiO2 are mentioned.

--
charles