Here at the School of Chemistry, we want to ensure that everyone knows something about the atomic scale of matter. As one of the largest chemistry departments in the country we make it our duty to tell the public about our research.
We want to make sure that some of the best and brightest young people choose to take up the challenges of our science so that one day they can provide solutions to the problems posed by modern life. These challenges come in the areas of healthcare, energy supply and sustainable new technology, to name but three.
We offer a wide range of demonstration lectures, talks, careers information and hands-on science activities to primary and secondary schools, as well as colleges and the general public. All of our activities are age-targeted.
Have a look at some of the demonstrations that take place as part of the Flash bang show, aimed at secondary school children.
Fire in ice
The white brick is a block of carbon dioxide, cooled to -78 ℃, also known as 'dry ice'. There's a pile of magnesium metal on it, burning away quite happily in the CO2. The formation of MgO is so favourable that it will strip O from CO2, leaving behind Carbon in the form of few-layer Graphene. Don't use a CO2 extinguisher on a metal fire!
Starting fire with water
In the tray there is a mixture of silver nitrate and magnesium metal powders. These are absolutely desperate to react with eachother. The magnesium will form a very stable lattice of MgO using some of the oxygen from the nitrate. However, because they are both solids they can't properly mix at the atomic scale. When a drop of water is added, this dissolves some of the silver nitrate, which kick-starts the extremely exothermic reaction.
When carbon burns, the flame is yellow, because excited carbon atoms release yellow light. If we excite other atoms, the colour they emit corresponds to specific energy packets which transport them from excited states to more stable states. These lines are characteristic of the element. Green for Barium, Orange for Sodium, and Red for Strontium. To get the excited atoms, we need energy from heat, so we need a fuel (here, icing sugar) and an oxidant (here, chlorate), all in the mix. This is rocket fuel; it would burn in outer space. It doesn't need oxygen from the air, there's plenty in the chlorate. This is the chemistry behind fireworks night. In our labs, you can measure the exact frequencies of light emitted, and see the direct experimental evidence for quantum theory.
Liquid to gas
We often need to keep things cold in a chemistry lab, so we use liquid nitrogen, which boils at -196 ℃. When a liquid boils, and turns to a gas, it takes up lots more room (about a thousand times more), which generates pressure as the molecules collide with the sides of their container. Here you see the pressure popping a balloon. Same thing would happen to your stomach if you drank any!