Question

look at the models of molecules below. select all the elementary substances. hydrogen hydrogen chloride hydrogen fluoride iodine fluoromethanol phosphorus tribromide

Explanation:

Step1: Recall definition of elementary substance

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

Step2: Analyze each molecule

Hydrogen ($H_2$) is made of only hydrogen atoms. Iodine ($I_2$) is made of only iodine atoms. Hydrogen chloride ($HCl$) is made of hydrogen and chlorine atoms. Hydrogen fluoride ($HF$) is made of hydrogen and fluorine atoms. Fluoromethanol ($CH_3FO$) is made of carbon, hydrogen, fluorine and oxygen atoms. Phosphorus tribromide ($PBr_3$) is made of phosphorus and bromine atoms.

Answer:

Hydrogen, Iodine