A1: Changes to the map of Europe
There are lots of historical atlases on the web; For example you might try the Euratlas website which has maps of Europe every 100 years.
Look carefully at the map of Europe in 1800. Which countries from the present day are missing? Which countries are bigger than they are today? Which countries are smaller? What does that tell us about countries in Europe?
Repeat the exercise for Europe in 1900. And for 2000. Which countries no longer exist? Which countries have replaced them? Can you think of a reason a country might disappear from the map of Europe? Can you think of a reason a new country might appear on the map?
Or you might prefer to look at maps of Europe in 1914 and in 1919, for example. What changes to the map of Europe happened as a result of World War One?
You could carry out the same activity for World War Two. Compare the map of Europe in 1919 with 1939 and then 1945. How has the map changed as a result of the Second World War?