The elements that have seven valence electrons are in Group 17 of the periodic table, also known as the halogens. These elements are:

* Fluorine (F)

* Chlorine (Cl)

* Bromine (Br)

* Iodine (I)

* Astatine (At)

Valence electrons are the electrons in the outermost shell of an atom, and they are the ones involved in chemical bonding. Halogens have seven valence electrons, which makes them highly reactive and prone to gaining one electron to achieve a stable octet configuration.