The compound fecl3 is made three molecules of iron chloride. one atom of iron and three atoms of carbon. one atom of iron and three atoms of chlorine. two atoms of iodine, one atom of iron, and one atom of carbon.

one atom of iron and three atoms of chlorine.  

Explanation: A compound is a pure substance formed by combination of two or more than two elements combined together in a fixed proportion by mass and can be decomposed into its constituent elements by chemical methods.

An atom is the smallest particle of an element which may or may not be capable of independent existence.

The molecule of compound is made by combination of one atom of iron and three atoms of chlorine. represents 1 molecule of ferric chloride.