The country in Europe with the greatest landmass is Russia. It is located in both Europe and Asia, but the majority of its land is in Europe.
Russia.
The Ruhr
The risk of nuclear explosions and radioactive wastes. Think of the Chernobyll Accident in the Ukraine. That happened in Europe in the late 80s.
Russia has the largest population in Europe. (110,000,000 in European Russia)
France
Moscow has the greatest population in Europe.
The cultural heritage of Europe is considered as Europe's greatest assets.
The Ruhr is Europe's greatest industrial comples
The country with the greatest number of immigrants can vary depending on the time period and specific circumstances. However, historically countries like the United States, Canada, Australia, and Germany have been popular destinations for immigrants from around the world.
France produces about 80% of its electricity by nuclear plants, but this is an exception in Europe, most countries with nuclear plants have about 20%, as in the USA. Not sure about Japan, but nuclear appeals there I think because they have little fossil fuels in the country. See www.world-nuclear.org for a more detailed survey.
Europe doesn't have the greatest number of earthquakes.