How Scientists Count

Or it's (nearly) all Greek to me

Counting is such an important part of maths that it is just about the first thing that you learn. Scientists need to count things too, and for most of the counting that they do, they use the same words and numbers that we do all the time.

But scientists also use some odd words for numbers. If you know a bit about this you will find it a lot easier to understand what your teachers are talking about, and we are here to help.

Have you heard of polythene? PVC (polyvinyl chloride)? Polymers? They all start with 'poly-' a Greek word that means many. Polymers are made up of a lot of repeating units of a smaller chemical to make big chains. Just like linking beads together to make a necklace.

The individual 'bit' of a polymer is called a monomer. Mono-, just like in monorail, is also Greek and it means one. (As an aside, the '-mer' part of polymer and monomer is also Greek, it means part).

If you join two parts together you get a dimer, three parts gives you a trimer, four parts a tetramer, five parts a pentamer and so on. In fact the number parts of the words for trimer (like triangle) and pentamer, hexamer etc. (like pentagon, hexagon etc.) are all the same, and come from Greek, except nonamer (and nonagon) which are still Latin. Scientists use tetra (Greek for 4) in this context, whilst mathematicians use quad (like quadrilateral) from the Latin for 4. Just to keep you on your toes sometimes (like biped and quadruped) scientists use the Latin words too.

The 'part' that the -mer refers to can be quite big. This picture of a tetramer is a protein that is made up of four protein subunits. It is still called a tetramer though.

It is not just scientific jargon, but quite often in our everyday language we use parts of Latin or Greek number words. For example a monocle, or a monorail (both use Greek), whilst a unicycle and a unicorn (both use Latin) and refer to the number 1. Bicycles use the Latin for two, whilst a dichotomy is the sort of situation in which you (and the ancient Greeks) felt they were being cut in two.

The more confusing words come with organic chemistry. If you've not started this yet, don't worry, you will, and with these simple facts you will find it much easier to get to grips with.

Long chain carbon compounds (5+ carbon atoms in a chain) use our old friendly number words from shapes, pent-, hex-, hept- etc.

But for the numbers 1-4 (again) scientists use yet more different words. Methane (CH4) has only one Carbon atom, and all things with one carbon atom use the meth- prefix. The name methane is derived from methanol, which comes from the Greek methe (wine) - hyle (wood), because methanol is produced when you distil wood.

Ethane (C2H6) is derived from ether meaning 'upper air.' Ether is a gas that is quite easy to make, and makes people fall asleep, and was thought to come from the upper air. Ether is a Middle English word, but it comes from the Latin and (again) the Greek aeither or air. All carbon compounds with 2 carbons in the chain have this 'eth'- prefix. (Actually when you look at the structure for ether, you will see it has two chains each with 2 carbon atoms in them, the modern name for ether is diethyl ether, just like in a dimer.)

Three carbons in a chain gives you propane (C3H8). The name propane is derived from propionic acid, (C3H7OOH), and propionic comes, yet again from the Greek, proto (first) - pion (fat), because propionic acid is the first organic acid to show fatty properties (it forms an oily layer in water etc.).

Finally, and the only one that isn't Greek, you get Butane (C4H10). Butane derives its name from its acid form, butyric acid. Butyric acid means, in Latin, 'the acid of butter' and it was first discovered in rancid butter.

Although there is far more to naming compounds than just these number words, at least with them you can get to grips with one of the hardest bits of the science syllabus and understand why people use these funny names.

In fact with all this information you should now be able to work out what Teflon is made of. Teflon (which is the non-stick coating on frying pans) is the trade name for polytetraflouroethylene. If we break that down, we have poly-, meaning many, and suggesting that we've got lots of copies of 'tetraflouroethylene' stuck together in a string. We then have -tetraflouro- which means four fluorine atoms (the tetra is four remember, flouro hopefully links quickly in your mind to fluorine). Finally there is ethylene, which starts with eth- which suggests it is a carbon based molecule with two carbons in it. It might take a while to sort out what is going on, but with a little patience it can help a lot with you understanding chemicals and their names.

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A note for those who know a bit more: All the alcohols, in modern nomenclature use the -ol suffix to indicate that they are alcohols (methanol, ethanol, propanol etc.). This is derived from the name of methanol, but if you look at the roots of the word methanol the '-ol' part comes from hyle or wood, in the original Greek, rather than the (more intuitively obvious) methe part which means wine. Just goes to show that we aren't always quite as reasonable as we ought to be.