select all the elementary substances. pyrite (fes₂) helium (he) tetraphosphorus (p₄) lithium chloride (licl)

Answer:

B. helium (He), C. tetraphosphorus (P₄)

Explanation:

Step1: Define elementary substance

An elementary substance is made of only one - type of atom.

Step2: Analyze pyrite (FeS₂)

It is composed of iron (Fe) and sulfur (S) atoms, so it is not an elementary substance.

Step3: Analyze helium (He)

Helium is an element, and it is made up of only helium atoms, so it is an elementary substance.

Step4: Analyze tetraphosphorus (P₄)

It is made up of only phosphorus atoms, so it is an elementary substance.

Step5: Analyze lithium chloride (LiCl)

It is composed of lithium (Li) and chlorine (Cl) atoms, so it is not an elementary substance.