My daughter was given a geology kit and has been busily tapping away with her mallet and chisel to release shiny semi-precious gems from large lumps of chalk. But what are minerals like these shiny gems made of, how do they form, and where are they found?
Air is mostly made up of a gas called nitrogen. But about one-fifth of the air (21%) is oxygen – the gas our bodies use when we breathe.
All living things need oxygen in order to stay alive but plants, algae and a group of bacteria called cyanobacteria, can also make oxygen. These plants, algae and cyanobacteria make more oxygen than they use and the extra oxygen goes back into the air. So, the oxygen is sort-of recycled, rather than used up.
Plants like trees use their leaves to make oxygen. But what if there were no trees left on Earth – would there still be enough oxygen in the air for us to breathe?
Oil is a type of fuel, which means that it is something we use to make energy. We burn oil to heat buildings and to make electricity, and we use it to make petrol and diesel for cars and other vehicles. There are also some rather surprising uses for oil, including chewing gum, lipstick and guitar strings!
But what is oil? How is it made? And does it really come from dead dinosaurs?
My daughter was hoping for a white Christmas but, given that we live in the warm, south-western corner of England, the chances of snow each winter are small and the likelihood of snow on Christmas Day is even lower. And even though we’ve had days when it’s been cold enough for ice to form on the car windscreen, I don’t think we’ve seen any snowfall for a year or two. So, what has to happen for it to snow?