The number 100 is a very significant one for human beings. It’s partly because our number system is based on ten – so ten tens seems to have a special significance. In years, it’s around the maximum lifetime of a human being, making a century more than just a useful division in the historical timeline. But in the natural world, 100 isn’t quite so important. There’s nothing about being element 100 that makes fermium stand out – the periodic table doesn’t attach any significance to base 10. But it’s hard not to think that fermium must be special in some way.