What is the difference in sodium and chlorine

sodium is a metal in group 1

chlorine is a non metal in group 7

sodium is a ionic compound

Chlorine is a nonmetal

(adding on to first answer)

resonant frequency

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.