Element 97 in our International Year of the Periodic Table series is berkelium. Berkelium is short on applications but is used as a target in the production of even heavier elements.

As we close in on the one-hundredth element graphic, we’ve finally gone past the last of those elements which are naturally-occurring. There’s some debate as to where exactly the cut-off point for this is, but most scientists agree it lies beyond uranium. It’s likely that the heaviest known naturally-occurring element is either plutonium or curium – though some sources do claim that berkelium occurs naturally, the evidence for this is lacking.

Berkelium, then, is produced artificially. This is accomplished in special nuclear reactors, and in very small quantities. Mere milligrams are made over several months, and it’s estimated that not much over a gram has been produced in the U.S. since 1967.

Why go to the trouble, you might wonder? Well, berkelium can be used as a building block for even heavier elements. It can be used as a target and bombarded with the ions of other elements. Most of the time, these other elements will bounce off, or smash the berkelium atom into multiple atoms of smaller elements. Every so often, though, the bombarding ion will stick to the berkelium atom, and create a new element.

Berkelium isn’t the only element used as a target, but it has been used to make a number of heavier elements, including the most recently discovered element, tennessine. We’ll meet more of the elements it’s helped to create over the coming days.

Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.