Question

look at the models of molecules below. select all the elementary substances. fluoride methanol hydrogen fluoride water boron trifluoride chloroform

Explanation:

Step1: Recall elementary substance definition

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

Step2: Analyze each molecule

• Fluorine ($F_2$) is made of only fluorine atoms.
• Methanol ($CH_3OH$) has carbon, hydrogen and oxygen atoms.
• Hydrogen fluoride ($HF$) has hydrogen and fluorine atoms.
• Water ($H_2O$) has hydrogen and oxygen atoms.
• Boron trifluoride ($BF_3$) has boron and fluorine atoms.
• Chloroform ($CHCl_3$) has carbon, hydrogen and chlorine atoms.

Answer:

Fluorine