 Unlike the previous group 17 elements, ununseptium may not exhibit chemical behavior common to the halogens. For example, extant members of the group routinely accept an electron to achieve the more stable electronic configuration of a noble gas, one having eight electrons (octet) in its valence shell This ability weakens as atomic weight increases going down the group; ununseptium would be the least willing to accept an electron. Of the oxidation states it is predicted to form, − 1 is expected to be the least common.
