Answer:
B. Quartz represents an element as SiO2
Step-by-step explanation:
A chemical element is a substance composed of only one kind of atom that determines its own unique properties that are different from that of other elements. An element cannot be broken down further as it represents the simplest form a substance can attain.
Chemical elements are usually labelled using symbols. These symbols contain only one capital letter for each element, which cannot excede two alphabets. For example, Silicon is an element with the symbol, Si while Calcium is an element with symbol Ca.
Note: in this question, Quartz (SiO2) is not an element but rather a compound because it is composed of two elements, forming a compound.