So copernicium, or copernicium as the discoverers would
prefer it to be pronounced, is the latest name to go up on the
periodic table and it is really very exciting because it is the
first time in as many years that a new name has appeared.
And not only has it appeared but quite excitingly, it has
appeared with a bit of controversy - what should the symbol
be? The first suggestion was that it should be called, the
symbol should be Cp, capital C with little p and that has got
really quite an argument inorganic chemists who use organic
groups in their compounds got quite excited because Cp is
the symbol that is used for cyclopentadienyl ion which binds
to all sorts of different metals and then it was discovered or
realised that, many, many years ago, Cp was used as an
alternative symbol for element number 71, lutetium, which in
some countries we called cassiopeium. And I’ve looked in lots
and lots of books that I have got at home and I can’t find one
of them that uses this name, but the reason why it is
important is because now more and more old papers, old
books are being digitised on the internet, if you start
searching for the symbol Cp it will start throwing up old
papers and cause confusion. So the decision has been made
by the International Union of Pure and Applied Chemistry or
the recommendation is that the symbol should be Cn, capital
C, little n. And I think that this is a very sensible suggestion
because it is unlikely that it can be confused with cyanide
which is capital C, capital N. And it is also nice for our Chinese
colleagues because Cn is the domain name for Chinese
websites and I think most chemists will be very happy with
that.
The element itself was first made quite a few years ago, and
it’s made like all these heavy elements by taking the nuclei of
two atoms that are lighter and banging them together and if
you are aiming for element 112 then you need to take 2
nuclei, which have atomic numbers which when you add them
together come up to 112, so in this case you take lead which
is atomic number 82 and so to get from 82 to 112 you need
to add 30, so you accelerate zinc atoms which have atomic
number of 30 towards these in a high speed accelerator and
every so often, and quite rarely, these two nuclei fuse
together to give you an element or an atom of element 112.
When you make the atom, it exists, for a short time which
might be a thousandth of a second, or a few thousandths of a
second or it might be as long as half a second or even a
second. And then the nucleus of the atom starts to decay.
Now it doesn’t blow into parts which are just protons and
neutrons in one great whoosh! But instead it starts going
down by steps, usually the atomic number changes by two
units or one unit depending what sort of particle is ejected
from the nucleus. So in the case of 112, and I don’t know the
details yet, it will decay. For example, the first step may be
going from 112 to 110 then the second step may be just one
unit to 109, and then two down to 107 and so on. Until you
get to an element below the mass of uranium the mass of 92
- which is stable.