14 November 2018
Dr Ann Hubbard, a member of the Royal Society of Chemistry, gave us an informative and entertaining presentation. Using ordinary everyday substances, such as cleaning materials and drinks, she demonstrated that chemistry is all around us. Reminding us of the chemistry we learned at school, that materials are all either solids, liquids or gases, she used models to demonstrate atoms and molecules.
Solids can be made waterproof or change characteristics, depending on the way the molecules are put together. Dr Hubbard showed how Goretex can let water-vapour (perspiration) out, without letting water (rain) in. As an encouraging aside, she mentioned that chemists are now working on making such plastic materials biodegradable.
Water has a very special molecule which enables it to be a liquid at room-temperature, but when it freezes at 0 degrees C, the solid ice sits on the surface rather than sink to the bottom. She also showed how another common household liquid, bleach, can be anti-bacterial and cleansing.
We all know about the common gases in the air, oxygen and nitrogen, but she showed how nitrogen can be used in a packet of crisps to keep the contents from going soft. She made a special plea for us not to waste the finite amount of the gas helium on balloons – it is much too special as it cannot be manufactured, only collected, and is an essential ingredient in MRI scanners. Finishing off with demonstrating the propellant power of hydrogen, she fired a plastic bottle filled with hydrogen across the hall.
Three male assistant chemists helped with the presentation but Dr Hubbard was the star performer, with an easy-going manner and a sense of humour.
For many years, Dr Hubbard has given such talks on everyday chemistry, modifying them to suit her audience and was awarded the Shaw medal for the dissemination of chemical science. She is willing to talk to schools, and other groups of young people, such as Cubs, Brownies and Scouts. She made a strong case for encouraging children (and your grandchildren) to pursue a career in chemistry – or other sciences.