Respuesta :

Selenium is a non metal, radon is a noble gas, silicon is a metalloid, and sulphur is a non metal. Hafnium is a transition metal.

Answer:

Hafnium

Explanation:

Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals