Re: How many ATOMS of element 112 have been made?

Hi there Kira,

Thanks for your very interesting question. Let's have a look at some of the so-called "superheavy elements", how they are made and how we detect them.

Starting with element 112, sometimes called ununbium, this element was made by accelerating atoms of zinc to very high speeds and directing them onto a target made from lead. Very, very rarely, if a zinc atom is moving at the right speed, it can fuse with a lead atom, like this:

²⁰⁸Pb + ⁷⁰Zn = ²⁷⁷Uub + ¹n

Lead (Pb) contains 82 protons, zinc (Zn) has 30, so Ununbium (Uub) has 112. You see also that a neutron is lost in this reaction, so the Uub isotope has a mass of 277.

You can find an excellent table of the elements at WebElements. If you go to the page for ununbium, it tells you that only a very few atoms of this element have ever been made. So how we detect them? Have a look at this article, describing the discovery of element 112. After the collision of the zinc and lead atoms, it was known how fast any atoms of Uub should be moving. This allows them to be captured. But the new atoms decay very fast, by emitting alpha particles (helium nuclei). It's possible to detect these alpha particles and measure their energies, as well as the decay products. In this way it was verified that an atom with atomic number 112 and mass 277 was formed briefly, before decaying in turn into elements 110, 108, 106, 104, 102 and 100.

The story is similar for elements 114, 116 and 118. Again, I recommend going to WebElements to find out about these elements. Element 114 was formed through the fusion of calcium and plutonium atoms, but this has yet to be verified by other researchers. Elements 116 and 118 were made at the Berkeley Lab, where Glenn Seaborg did much pioneering research into heavy elements. In each case, the atoms were detected by looking at the alpha particles released during decay and the decay products. Only a very few atoms of these elements have ever been made.

If you want to know more details, try this chapter of the excellent website, The Wonderful World of Atoms and Nuclei.

Hope this helps with your question,
Neil Saunders