Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: Wyatt Dick on 05/07/2013 22:08:22

Title: What are the correct pronunciations and conventions for chemical terms?
Post by: Wyatt Dick on 05/07/2013 22:08:22
We are doing some voice work for a Japanese scientist. Below is an excerpt from some of the text we have to put into words:

Under air conditions, ground-state oxygen molecules (3O2) are degraded by 185 nm UV to (ground-state) atomic oxygen O(3P), which then reacts again with molecular oxygen to generate ozone (O3). The ozone is degraded by 254 nm UV and becomes an excited oxygen molecule (1O2) and an excited oxygen atom (O(1D)). Therefore, continuous generation of AOS is possible through the generation of ROS and O3 by 185 nm UV, and the conversion of O3 to AOS by 254 nm UV. Since both the 1O2 and O(1D) are AOS, strong oxidizability is predictably generated by exposing a target to the AOS.

I am unsure what the conventions would be for verbalizing such substances as:

"ground-state oxygen molecules (3O2)". (Should be superscript "3", then "O', then subscript "2".)
How would a chemist pronounce that? Would he say: "ground-state oxygen molecules, or triplet oxygen"? Or would he say "ground-state oxygen molecules, or three-oh-two"?

I have similar questions regarding "excited oxygen molecule (1O2)" and "an excited oxygen atom (O(1D))".

Any help would be appreciated.
Title: Re: Chemistry Naming/Pronunciation Conventions
Post by: alancalverd on 06/07/2013 02:14:40
I suspect this sort of passage would only occur (a) in the presence of a written text or diagram, as in a lecture or tutorial, or (b) in conversation between people who know each other's work and have adopted a common jargon. In either case, "three oh two" would be said because it triggers (a) attention to the written symbol that best resembles the sound or (b) a recollection of previous discussions and definitions.

In formal writing you would use the descriptive term "ground state oxygen" followed by the standard notation using actual superscripts and subscripts, in brackets.
Title: Re: Chemistry Naming/Pronunciation Conventions
Post by: evan_au on 06/07/2013 06:31:31
3O2 should be written as 3O2. I would say it as "3 molecules of Oxygen (Oh-two)".
Ozone should be written as O3, but I would say it as "Ozone (Oh-three)".
254nm is pronounced "2hundred and fifty four nanometers"
I would expand AOS and ROS in full the first time, then the acronym is fine after that.
There is no substitute for someone who has the domain knowledge in the target language, I'm afraid.
 
Title: Re: Chemistry Naming/Pronunciation Conventions
Post by: Wyatt Dick on 06/07/2013 13:19:47
Thanks for the help. Unfortunately, I don't know how to add super- or subscript on this board, but in the actual text such formatting has been done. I'm primarily concerned with what would be verbalized, and I cannot confirm that there will always be a written slide used in conjunction with the audio.

But given that each formula is preceded by its description, it seems to make sense that orally one would sound out the formula, as in "Ozone, or Oh-three". Or in the other case, "ground-state oxygen molecules, or three-Oh-two". The one aspect that still worries me is sounding out the number before the element, the number in superscript. I know that the number in subscript--the number identifying the number of atoms--is usually sounded out simply, as in "H-too-oh". But to be honest, I'm not quite sure what the superscript number represents, and whether it would be confusing to sound out both the superscript and subscript numbers in the same way, e.g. three-oh-two?
Title: Re: Chemistry Naming/Pronunciation Conventions
Post by: alancalverd on 06/07/2013 18:52:17
You need to see it properly typeset or handwritten to know what is going on. It wasn't clear whether your 3O2 is supposed to be 3O2 - some kind of excited state of the O2 molecule - or 3O2 - three oxygen molecules.

Now 3O2+hv -> 2O3

would be read as "three molecules of oxygen, with photon excitation, form two molecules of ozone" which everyone understands! (sorry, I've found the superscripts but not the greek nu)

Generally, a preceding upper case numeral means "number of", and a succeding subscript means "number of atoms in the molecule", hence 6H2O means six molecules of water, each containing two atoms of hydrogen and one of oxygen". However other superscripts can indicate atomic number, atomic weight, or states of ionisation (usually as e.g. N3- "a triply negatively ionised nitrogen atom") or excitation (e.g. m means "metastable") and the interpretation may vary with context.

Fortunately, as I said earlier, most audiences are likely to be familiar wth the jargon in context. The universal language of science is Broken English and we all enjoy its "wegional wawiants" and applaud anyone who has a go - as long as his visuals are correct! It is however unforgiveable to use a TLA without PD.
Title: Re: Chemistry Naming/Pronunciation Conventions
Post by: Wyatt Dick on 06/07/2013 20:51:47
Thanks to you, I've found the superscript and subscript functions!: I3O2.

I understand what you are saying about how what is "correct" is context driven. But we're not likely to get much more context than the fact that it is a biochem paper, so I'll have to go with a best guess.

If you were reading the phrase: "Under air conditions, ground-state oxygen molecules (3O2)", how would you verbalize the portion in parentheses? Again, best guess without knowing the local jargon.
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: chris on 06/07/2013 22:19:27
That cannot be right; the "3" should be on the same level as the O and is used to communicate the number of molecules or atoms of a chemical species; superscripts ahead of a species imply isotopes. There is no 3 isotope of oxygen, so that has to be wrong...
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: alancalverd on 07/07/2013 01:27:52
Good old Wikipedia

Quote
Singlet oxygen (or 1O2) is the common name used for an electronically excited state of molecular oxygen (O2), which is less stable than the normal triplet oxygen. Because of its unusual properties, singlet oxygen can persist for over an hour at room temperature, depending on the environment. Because of differences in their electron shells, singlet and triplet oxygen differ in their chemical properties. Singlet oxygen is highly reactive.

The answer is, therefore, that you can't verbalise the shorthand, but you can shorthand the verbals. Nothing new here: whether you are learning Pitman, Mandarin or chemistry, you learn the written or spoken words (or physical concept) and represent them by a squiggle, but nobody unfamiliar with the language (or physical chemistry) could voice the squiggle as a sound. 

In this particular instance you might say "three oh two" but only in an expert conversation or if accompanied by a clear visual. Colloquially, out of context and with no typescript, 302 is the second room on the third floor!
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: Wyatt Dick on 07/07/2013 09:23:21
I understand we need some context, or as you say, we get hotel room numbers.

What I meant is that we only have the general context of chemistry to work with, but not anything more specific in terms of working jargon. So based on what has been said, we seem to have two options so far. Would we verbalize "ground-state oxygen molecules (3O2) as:

(a) ground-state oxygen molecules (three-oh-two)

or

(b) ground-state oxygen molecules (triplet-oh-two)

Same for O(1D): is it oh-one-dee or oh-singlet-dee? And would the parentheses around the "1D" affect the verbalization?
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: Bored chemist on 07/07/2013 09:33:50
That cannot be right; the "3" should be on the same level as the O and is used to communicate the number of molecules or atoms of a chemical species; superscripts ahead of a species imply isotopes. There is no 3 isotope of oxygen, so that has to be wrong...
Nope, the superscript 3 prefix is correct and it's used to show the electronic state of the molecule (or atom in some cases).

It's right, but it's yet another convention- one you didn't know about.
This
(3O2)
is a "triplet oh two" molecule or "triplet oxygen"
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: Wyatt Dick on 07/07/2013 10:11:43
Hmm...I'm now appreciating an earlier point, which is perhaps the parentheticals are purely for written communication. That is to say, given the formulas are preceded by an English description, perhaps the formulas in parentheses are simply omitted from any verbalization of the text. We don't usually verbalize "water (H2O) as "Water (H-two-Oh)", we just say "water". The "H2O" may only be there to be seen.
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: alancalverd on 07/07/2013 12:06:16
It's more complicated than that!

We begin with some quite complicated discovery or hypothesis like the excited state of a water molecule, and devise a verbal descriptor ("the excited state of a water molecule") and a written shorthand (1O2).

Both of these are mappings, and the universal feature of mapping is the loss of dimensionality. We retain only those features that are important to the user. Hence an ordinary geographical map may show road numbers, river names, vegetation, geology, or just airways, beacons and control service boundaries with no surface features at all, depending on who needs to know.

Learning to drive, fish, farm, mine or fly involves learning to interpret the map appropriate to your chosen activity and learning the spoken words that two users of the  same map would use to communicate. Thus "Airway A5" means something quite different to a physiologist  and an aviator, and nothing at all to the man in the street who hasn't seen either map. 

Which brings me back to my original point: "three oh two" is absolutely explicit in context between experts,  and meaningless (or at best ambiguous, as we have seen) otherwise.
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: Bored chemist on 07/07/2013 13:12:48
"Which brings me back to my original point: "three oh two" is absolutely explicit in context between experts,"
Not quite.
3O2 (triplet state)
is different from
3 O2  (which is what 2 ozone molecules decompose to).



Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: alancalverd on 07/07/2013 23:41:05
That's why you need context, and experts. The problem was, how do you read 3O2 out loud, however it is written?

Your pseudonym implies expertise in the field, but without context, you are almost as lost as any numpty.
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: Bored chemist on 09/07/2013 19:43:52
The point remains that reading the first character as "triplet" because it's superscripted is only possible because (1) you know the convention but also (2) because it's superscripted.

The experts simply wouldn't say "three oh two" if they meant triplet dioxygen.
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: damocles on 09/07/2013 23:33:43
There is enough of a context in the text
"Under air conditions, ground-state oxygen molecules (3O2) are degraded by 185 nm UV to (ground-state) atomic oxygen O(3P), which then reacts again with molecular oxygen to generate ozone (O3). The ozone is degraded by 254 nm UV and becomes an excited oxygen molecule (1O2) and an excited oxygen atom (O(1D)). Therefore, continuous generation of AOS is possible through the generation of ROS and O3 by 185 nm UV, and the conversion of O3 to AOS by 254 nm UV. Since both the 1O2 and O(1D) are AOS, strong oxidizability is predictably generated by exposing a target to the AOS."
to enable a chemist to say with some confidence that it should be read "triplet-oh-two", "oh-triplet-P", "oh-3", "singlet-oh-2", and "oh-singlet-D"
Title: Re: What are the correct pronunciations and conventions for chemical terms?
Post by: damocles on 09/07/2013 23:51:00
According to Chris (Reply # 6):
Quote
That cannot be right; the "3" should be on the same level as the O and is used to communicate the number of molecules or atoms of a chemical species; superscripts ahead of a species imply isotopes. There is no 3 isotope of oxygen, so that has to be wrong...

Technically chris is quite correct -- the spectroscopic notation should follow the molecular descriptor in parentheses. However chemists usually shorten the notation by a superscript in front of the molecular descriptor

(especially if they, like me, cannot remember whether the correct spectroscopic term for ground state molecular oxygen is triplet-pi-you or triplet-sigma-you-minus etc.!)
---
actually it is oh-2-parenthesis-triplet-sigma-gee-minus-close for the ground state, and oh-2-parenthesis-singlet-delta-gee-close for the excited singlet state.

www.rz.uni-frankfurt.de/~rsch/1O2-english.html‎