Listen to Mark Lorch's Four Thought podcast (.mp3) (about 20 minutes) on this same topic — definitely a must for chemistry teachers.
Reprinted from BBC News magazine:
I really enjoy my job, I'm a chemist in academia. I get to wallow in the fascinating world of research science and then pass on my passions to eager young minds.
But my job is even better than that. I'm an academic who gets let out of my ivory tower and into schools, shopping centres and festivals where I perform all the most entertaining chemistry. And I pull out all the stops — liquid nitrogen gets sloshed around in abundance, hydrogen balloons are ignited like mini-Hindenburgs and ethanol-fuelled rockets zip around the playgrounds. Chemistry is fun.
So why is everybody scared of chemicals?
Because we are, aren't we? The very word chemical is often synonymous with toxin or poison. We use phrases like "it's chock-full of chemicals" to imply something is artificial and bad for you.
Meaningless slogans like "chemical-free" pop up on products in health food stores and billboards. And nobody seems to mind, least of all the Advertising Standards Authority (ASA). I know — I've complained to them and they told me that consumers clearly understand that "chemical-free" really means "free of synthetic chemicals".
I don't get the distinction. Why are synthetic chemicals worse than natural ones? Why is the synthetic food additive E300 bad, while the vitamin C in your freshly squeezed glass of orange juice is good? (Even though they are both the same thing.)
Chemistry is fascinating because of the way it can be used to synthesise new stuff — it's like molecular Lego. The fact that everything is made from 100-odd building blocks is remarkable. Throw chemicals in a pot in the right way and you can build the world around us.
So why is chemistry the bad boy of the sciences? Why is there this chemophobia?
Biology doesn't get a bad rap — quite the opposite. Biology has amazing animals, plants, the human genome project and David Attenborough. It's natural and good.
What about physics? Well, physics is just pretty damn cool. It's got stars, lasers and the most impressive machine ever built — the Large Hadron Collider. All fronted by Brian Cox beautifully explaining the wonders of the universe. It doesn't get any cooler than that.
And then there's chemistry which, by reputation, has pollution, poisons, and weapons so bad that they warrant a Nobel Peace Prize-winning organisation to control them. And the closest thing we've got to a celebrity chemist comes from the drama Breaking Bad, where Walter White, a chemistry teacher turned drug kingpin, uses his encyclopaedic chemistry knowledge to synthesise hard drugs, poison his enemies and dissolve the bodies of his victims. He doesn't really do much to combat chemophobia.
To me, chemistry's bad reputation seems very odd. Consider the estimated 1,300 deaths in Syria as the result of sarin gas. They were, of course, absolutely horrific. But why were they worse than the 100,000 deaths caused by conventional, physical weapons?
And closer to home what's the most likely cause of injury or illness? I'm willing to bet my house that if you've been laid up in bed lately, it's been due to some biological bug or physical injury and not any sort of chemical-related poisoning. And what do you take to ease the symptoms of that dreadful stinking "natural" cold, sprained ankle or pounding headache? Some chemical analgesic, of course.
It is true that chemicals can be dangerous. My horticulturist grandfather taught me that. He had a smallholding (a plot of land too small to be called a farm) with a large brick outbuilding that housed his lab. He'd assembled the contents over years of amateur experimenting with plants and soils. To a 10-year-old fledgling chemistry geek, it was an Aladdin's cave of strange instruments, bottles and weird muddy mixtures.
Some grandfathers' idea of a treat for their grandchildren is a chewy toffee. Not mine. If we were really good, he'd get out his sodium metal, mysteriously sitting in its jar of oil (he'd acquired it sometime in the distant past when health and safety wasn't quite what we know and love now). Then he'd gingerly take it to a quiet corner of his plot and, with a long pair of forceps, he'd carefully extract a lump of the soft glistening metal before hurling it into a bucket of water. FIZZZZZ, BANG!
Maybe you had a chemistry teacher who was fond of that demon- stration. But trust me, my grandfather did it bigger and better.
So Grandfather taught me that chemicals can be dangerous, and if something dreadful had gone wrong in his makeshift lab, then no doubt the papers would have reported on the role of chemistry. But what if Grandpa had been negligent with the upkeep of the railings around his balcony? What if someone had fallen off, gravity accelerating them at 9.8 m per second per second, until they hit the hard ground below? Would anyone have described it as an awful physics accident?
So why does chemistry's role in accidents get highlighted, and whose fault is it that people are so scared of chemicals?
Simple — mine.
It's my fault, and my grandfather's. We are responsible for chemophobia. Why? Well, Grandfather's sodium demo certainly fuelled my enthusiasm for chemistry. But it didn't spark it — that happened somewhere else. And sparking an interest is what he should have done and what I should be doing.
Pouring fuel onto the flames of enthusiasm is easy, especially with chemistry. The theatre is easy, too — the bangs, the flames, the explosions, the pops, the whizzes, the smoke and the rockets are fabulously entertaining. I love it, and I love the whoops and cries and applause from the audience.
But at the end of the day, what did the audience remember? Just those bangs — and not a jot of chemistry. Explosive, flaming chemistry demos do nothing to show what chemistry can build and everything to highlight what it can destroy. And in the process, they blow out any flickering interest in chemistry and replace it with fear.
Instead of listening to the boys asking for more explosions, I should have paid attention to the girl at the back with her hands over her ears. I should have shown her how easy it is to do fascinating chemistry safely.
Soak a bit of red cabbage in water and you have a powerful pH indicator that miraculously changes colour when you add vinegar. Or get some sodium bicarbonate, mix it with some aluminium foil and you can chemically clean up your silver spoons. Take two pencils, attach them to a 9 volt battery and put them in a glass of water. You get bubbles forming on the pencil lead — hydrogen on one pencil and oxygen on the other. And if you collect those bubbles, you get twice as much hydrogen as oxygen — proof of the formula for water, H2O.
Then I should have told the class about the fascinating stories tucked away in the history of chemistry. Like Georgy de Hevesy concealing his friends' solid gold Nobel Prize medals from Nazis. He didn't want to risk burying them or simply hiding them somewhere. So he used chemistry. He dissolved the medals in a mixture of hydrochloric and nitric acid, and then he popped the bottles on the shelves of his laboratory, hiding them in plain sight.
The Nazi troopers, hunting for loot, marched straight past them. Then in 1945, De Hevesy used another simple bit of chemistry to recover the gold. He returned the metal to the Nobel prize committee who had those medals recast and returned to their rightful owners.
Those are the demonstrations that fire imaginations and fuel a love of chemistry. Those are the stories that kill chemophobia.
