For some students, I have found that abstract concepts, such as the structure of the atom, can be difficult to grasp. Despite making mobiles and colourful posters, and looking at endless numbers of examples, some pupils still struggle to understand the relationship between electrons and atomic structure. By acting out particles in an atom, they can explore the ideas kinaesthetically, and this helped many of my students.
To act out an atom, you will need a few sets of different coloured sports bibs, a copy of the periodic table, pens and A4 paper. The class should be in a large space, such as a playground or a hall. For each example you want them to act out, they must look at the periodic table and write the number of protons on one sheet of paper and the number of neutrons on another.
Two students should be chosen to represent the nucleus - one for the protons and the other the neutrons. For each example of an element, one of them holds up the paper showing the number of neutrons and one holds up the sheet showing the number of electrons. The rest of the class get into teams of two and eight, to represent electrons in the atomic shells. Each group wears a different coloured bib.
I start by acting out hydrogen. Pupils decide how many electrons are in the first shell. One child then walks around the "nucleus" to act as the one electron in the first shell. We then move on to more challenging atoms.
This model can be extended to show the shielding effect of electrons, with those in the outer shell being further away from the nucleus (positive pull) or finding it difficult to "see" the nucleus as there are inner electrons in the way. By using this model, the reactivity of elements in groups 1 and 7 can also be compared.
A photograph of each "atom" can be taken with a digital camera and shown in the next lesson using a data projector and interactive whiteboard. Students can then annotate their picture to show the electron shells clearly, and even guess which atom is being shown.
Sam Holyman Swanshurst School, Birmingham