Wednesday 9 March 2011

Some questions about Beryllium

Blogger Grrlscientist is currently posting blogs about the elements, using one of our videos each week.

Her recent post about Beryllium prompted a few questions from her readers.

You can see the post in question here.

We get asked dozens of questions every day and it's impossible to deal with all of them... But in this case I asked our experts to respond.

Here is what they said:

Professor Poliakoff wrote
: "The question about the stability of atomic masses 4, 12, 16, is interesting and concerns an area miles away from my expertise, namely the synthesis or, if you prefer, birth of elements inside stars. The process which begins with H atoms and then involves fusion i.e. H2 + H2 --> He In the end the abundance of different isotopes depends on both the fusion reactions occurring in the stars and also on the relative stability of combinations of different numbers of protons and neutrons. The overall result is more complex than just multiples of 4. However, I don’t know enough to explain it further – even professors have their limits."

Dr Debbie Kays said: "There is a relatively low cosmic abundance of stable isotopes of Be (and also Li and B, actually) in the universe. The lack of 8Be is in contrast to other elements with atomic masses with multiples of 4 (such as 12C, 16O etc). 8Be is formed by helium burning reactions in stars but it is very unstable (with an extremely short half life). Although I’m not a nuclear physicist, it seems that 8Be is so unstable due to the fact that when it decays via alpha emission it produces two stable, self-contained 4He atoms which drives this decay process. In stars, the transient 8Be can also undergo a reaction with another 4He atom to form 12C, as LarryJayCee described, which can then undergo further reaction with another 4He to form 16O.

"The most stable isotope of beryllium is 9Be. This isotope is likely formed by fragmentation reactions in space, which can happen when high energy heavier elements in cosmic rays collide with the 1H or 4He atoms in cosmic gas and break apart.

"I didn’t know that there are speaker models out there which have beryllium in them! They seem to be pretty expensive from what I can see, this may well be due to the quality of the sound obtained from them, but also might due to the challenge of handling toxic beryllium reactants. I’m not sure of the advantages of having these speakers as I’m not a connoisseur of music but I assume that you can obtain higher frequencies with them due to the low molecular weight of beryllium."

Here is our Beryllium video:

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