The element that exhibits both electrovalency and covalency is

Chlorine with metals forms electrovalent bond (or) ionic bond and with non metals forms covalent bonds and hence it exhibits both electrovalency & covalency

ex :-

→ "Ne" donot form bonds due to stable octet configuration and hence dodnot exhibits valency.

→ Na & Ba are metals , they  forms only ionic bonds & exhibits electrovalency.