The element silicon is hard and brittle crystalline solid with a blue-gray metallic luster. silicon is used as a semiconductor. based on these properties as well as the location in the periodic table, we would classify silicon as a a) metal b) nonmetal c) metalloid d) rare earth element

C) metalloid

Explanation: Metals are the elements which can easily lose electrons and are hard, ductile and possess luster. They are good conductors of heat and electricity.

Non metals are the elements which can easily gain electrons and are soft, non ductile and do not possess luster. They are insulators of heat and electricity.

Metalloids are the elements which have intermediate properties between those of metals and non metals and are called as semiconductors.

Thus Silicon is a metalloid.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

1. is geographic distribution

2 is increasing complexity

3 is transitional forms