Again we had a group of pupils visiting us to make salt prints of photos that were printed in black and white on transparent plastic (like in overhead projectors – if anyone is old enough to remember those). This time the visitors were a group from a primary school here in Warsaw (Podstawow a z Oddziałami Integracyjnymi Nr 301 im. Janusza Korczaka) accompanied by their chemistry teacher Karolina Kopka.
I like this demonstration, since it’s a good example of charge transfer in practice, without the need for electrodes and apparatus; it has lots of hands-on elements; and the kids can bring some nice prints home. For a description of exactly what we did, you can check the post from the first session, about two years ago.
We also took the pupils to have a look at some plants and an unfortunate bug. The chance to see such things in several thousand times magnification is usually very appreciated.