which of the following elements is a metalloid with moderate reactivity? a. copper (cu) b. sodium (na) c…

Brief Explanations:

Metalloids have properties intermediate between metals and non - metals. Copper is a metal, sulfur is a non - metal, sodium is a metal. Silicon is a metalloid with moderate reactivity as it can exhibit some metallic and non - metallic characteristics.

Answer:

C. silicon (Si)