Question

classify each of the following pure substances as either an element or a compound: nickel, copper, silicon dioxide. use the references to access important values if needed for this question.

Explanation:

Step1: Recall element - compound definitions

An element is a pure substance made of only one type of atom. A compound is a pure substance made of two or more different types of atoms chemically combined.

Step2: Analyze nickel

Nickel has the symbol Ni and is made of only nickel atoms. So it is an element.

Step3: Analyze copper

Copper has the symbol Cu and is made of only copper atoms. So it is an element.

Step4: Analyze silicon dioxide

Silicon dioxide has the formula SiO₂. It is made of silicon and oxygen atoms chemically combined. So it is a compound.

Answer:

Nickel: Element
Copper: Element
Silicon dioxide: Compound