Which of the compounds is composed of Al, Si, O and H?

A.

Epson salt

B.

Limestone

C.

Clay

D.

Urea

Correct answer is C

Between the five main minerals found in clay, kaolinite is the most common. Kaolinite holds the chemical composition Al\(_{2}\) Si\(_{2}\)O\(_{5}\)(OH)\(_{4}\) and is an aluminum silicate material with a low “shrink-swell” capacity. It is a soft, white mineral but is often colored orange or red by iron oxide found in the soil.