Europium (Eu)

            (https://en.wikipedia.org/wiki/Europium#/media/File:Europium.jpg)

Properties

Europium is the most reactive element of the REE group. It is also the rarest. Very little is understood of this element and it's future potential.

Europium is an elemental superconductor at 1.8 K and 80 GPa. This is very odd because Europium is also extremely magnetic, or unsuperconductor-like. This is where the immense pressure of 80 GPa comes into play. That much pressure causes the internal structure of Europium to reorganize, and in doing so, looses enough electrons to also loose magnetism. If we only needed a superconductor at the center of the moon...

Like Dysprosium, Europium has a high thermal-neutron absorption cross section. In other words, it is extremely good at absorbing free neutrons flying around.

Applications

Have you seen the new Euro? It is printed with traces of Europium, which causes the note to glow red when put under a UV light. What a fitting name.

Other uses of trace amounts of Europium include low energy light bulbs, thin superconducting alloys, and doped laser plastics (whatever those are).