# Is it tennessINE because it has 117 electrons or because it behaves like a halogen?

The NPR News podcast and transcript The Convoluted Story Of How The First Atoms Of Tennessine Were Created includes the following exchange between science reporter Joe Palca and Oak Ridge nuclear engineer Julie Ezold:

PALCA: In other words, in five months, they only got six atoms of tennessine. When I first heard that name, I thought it was a mistake. All the other synthetic elements ended in -ium - think plutonium or americium. Oak Ridge nuclear engineer Julie Ezold understands my confusion.

JULIE EZOLD: We all thought it was going to be that way as well. But remember - the periodic table has rules.

PALCA: Ezold says Element 117 fits in a column of the periodic table filled with compounds called halogens - fluorine, chlorine, bromine.

EZOLD: Therefore, its name had to end in -ine. So instead of tennessium (ph), it's tennessine.

The more I thought about this, the more I questioned how elements discovered in the future might or might not be classified as halogens, especially if an "island of stability" is ever found and even more elements are discovered.

• Is there really a rule or at least a firm guideline that ultimately requires the name of element 117 to end in -ine simply because it has 117 electrons?
• Or was it somehow necessary to experimentally demonstrate some chemical property associated with halogens?
• Or would an atom with 117 electrons certainly and without question behave like a halogen?
• Or will all current and future elements that obeys certain numerical rules be called halogens no matter how they behave chemically?
• I can't find any tags like naming, convention, rules or regulations – uhoh Dec 7 '19 at 2:39
• I found Nomenclature. – Oscar Lanzi Dec 7 '19 at 3:23
• It's worth noting that we see the same thing with element 118: it falls in the noble gas group and, consistent with this, ends in -on instead of -ium: oganesson. See: en.wikipedia.org/wiki/Systematic_element_name – theorist Dec 7 '19 at 4:47
• It comes after Astatine so it is a kind of halogen, in the sense that it has expected valence configuration ns2np5. It is expected to be rather metallic/metalloid. – Alchimista Dec 7 '19 at 8:49
• It is thought that tennessine will have very different chemistry from the lighter halogens. Astatine would already be something of an oddball, if only it could be isolated in reasonable amounts. The discontinuity of the chemical properties between the last common halogen (iodine) and tennessine would be very stark indeed. – Nicolau Saker Neto Dec 7 '19 at 21:04