This is the second in a series of posts about the sciences I’ve studied. Later posts will cover earth sciences, psychology and neurophysiology, physiology, ecology and information science.
I suppose chemistry is what got me interested in science in the first place, and I’ve done a lot of courses in various aspects of the subject – organic chemistry, inorganic chemistry, biochemistry, geochemistry. So what’s it all about? Well, a bald summary would be that it’s about the nuclear and electronic characteristics of atoms. The characteristics which determine their interactions depend on structures and energies.
What turned me on was the first chemistry lesson at my secondary school. The teacher set fire to a pile of ammonium dichromate on the bench, and it produced a little volcano. He lit a piece of magnesium ribbon, and we were dazzled by the brilliant white light it produced. He set fire to a mixture of hydrogen and oxygen in a reaction vessel, and the bang was deafening. He dropped a piece of potassium metal onto a jar of water, and we watched it melt into a ball, catch fire with those lilac flames, and fizz over the surface before it popped. The sights, sounds and smells were pretty gee whizz stuff, and I suppose with the demands of Health & Safety today’s 12-year olds won’t see it, but I was hooked.
I joined the Scottish Schools Science Club, and attended a lecture given by Sir George Porter. He demonstrated how light could be used to produce chemical reactions – flash photolysis, clockwork reactions and the like. There was a chemical supplier – Baird – who had a shop, now demolished, behind the Museum in Chambers Street, and they sold ‘fourpenny boxes’ of chemicals, even to schoolchildren. So I experimented at home, making a variety of whizz-bangs with coloured sparks. The mistake I made as a teenager was in thinking that I’d want to make my life in the subject. After leaving school I went to the then Heriot-Watt College to study chemical engineering. I realised in that first year that I wasn’t cut out for it, and I dropped out. I had enjoyed the organic chemistry part of the course, especially the lab work. I became a bit of a ‘beat’, working in bars, writing bad poetry and playing the alto sax (badly too).
It wasn’t until the start of the Open University in 1971 that I renewed my interest in the subject, taking courses in inorganic chemistry, organic chemistry with biochemistry, geology with geochemistry, plus several other subjects I’ll mention later.
The reactivity of atoms depends to a large extent on the nature of their outer shells of electrons; they tend to ‘want’ to fill these shells to particular values, by losing electrons to other atoms, or gaining electrons from them. A filled shell is a stable shell, having a lower energy level than excited states. The so-called ‘noble’ gases have filled outer shells in their own right, so they are exceptionally stable and unreactive. I’ve used this fact in a poem about neon, after which I’ll stop.
The new one (Ne)
From chilled liquid air
three gases boiled off –
the strange one, the hidden one,
and the new one.
Injected into pumped-out glass tubes
it glows orange-red, and very brightly,
when a current’s passed. Did anyone count
the numbers of new cars sold
thanks to words made of light?
If nobility comes from disdaining attachments,
then call it noble, but it’s a sterile aristocracy
with no family, no descendants,
all shells filled, and no spare hands
The ‘strange one’ was Xenon, and the ‘hidden one’ was Krypton. Ramsay and Travers isolated all three from liquid air. Neon tubes were first used commercially to sell Packard automobiles.