You want to know a super cool thing about humanity? We have found ninety-eight naturally occurring elements in the world. That starts with hydrogen with one proton and ends with californium with ninety-eight protons (we really synthesized californium before we discovered it in nature, but that’s besides the point). Here’s the badass part: in the 1950’s, we decided that ninety-eight was not enough and started making our own elements. We are now up to element 118, with the wonderfully temporary name of ununoctium. Most of these elements fall apart quickly, but a theorized island of stability may just be over the horizon.
These synthesized elements have half-lives ranging from just over a year to mere fractions of a second. For those unfamiliar with the concept of half-lives and radioactive decay, radioactive decay involves the nucleus of an unstable atom emitting a particle of some sort. A half-life is how long it takes for half of the material in a mass of unstable atoms to decay. So it’s sort of a measure of how stable a nucleus is: the more stable it is, the longer the half-life.
But, oh ever-observant reader, you ask why would a nucleus be unstable? I’ll tell you why: the nucleus of an atom is a bit like a balloon: if you put too much air in it, it will pop at the slightest provocation. In the same way, if you put too many particles (neutrons or protons) into an atom’s nucleus, it becomes unstable and will decay at the slightest provocation. And the man-made elements that we have created have a LOT of particles in their nuclei. Element 118 has an atomic number (the number of protons) of 118 and an atomic mass (the mass of the neutrons, protons and electrons in the atom) of about 294. That’s a lot of stuff, compared to something like carbon which has an atomic mass of about 12. So it makes sense that the elements that we have created would be rather unstable: they’re really heavy.
That balloon analogy isn’t entirely correct, though, because scientists suspect that if we get atoms big enough and with just the right number of neutrons, they might start getting stable again. Relatively stable, anyway. They’ll probably still be radioactive, but they’ll last longer than the milliseconds that we see now.
The problem is how hard it is to create these new elements. The only way to make them is to smash already very heavy elements together in a particle accelerator and only a few atoms are made at a time. The sci-fi fan in me wonders what properties these theoretical new elements would have, if we can eventually create them in mass quantities. John C. Wright wrote about building rings around Jupiter and the Sun, which were used as particle accelerators in his series The Golden Age. Can you imagine the stuff we could do? The science we would discover? A nerd can dream.