I used this as a stretch activity for top year 10's. It is a problem solving activity that requires an understanding of the concepts of ionic and covalent bonding. Encourages pupils to apply their knowledge! ( The answers are X = Sodium, Y = Carbon and Z = Chlorine). P.S. I know that some of the statements are not necessarily true, but they are for the purpose of GCSE chemistry!

This tarsia covers a variety of chemical word equations - designed with OCR 21st century science C6 in mind. If pupils finish it quickly you could extend by getting them to write balanced symbol equations for the word equations in the tarsia.

For KS3 Biology (maybe KS4) - Reproduction section. I printed these images onto 1 sheet of A4 and got my year 7 class to discuss and annotate each of the images. The first one showing a regular baby - they had to label. The second shows twins that appear to share an amniotic sack - so potentially (not necessarily) mono-zygotic. The third shows twins that are in 2 separate amniotic sacks (potentially?) so are di-zygotic. The fourth shows conjoined twins. The pictures brought out some really interesting questions and discussions from my class!