Which of these terms might be a chemical compound? iron floride helium neon?

Iron Fluoride 

A chemical compound is a substance composed of atoms from two or more (different) elements. These compounds are formed by the creation of chemical bonds between the atoms of the different elements. 

Helium and Neon are both elements, and in particular, they belong to a group of chemical elements called noble gases. Being noble gases, they are very stable and do not react easily. 

Iron fluoride is a chemical compound consisting of the metal, iron, and the nonmetal, fluorine. When a metal and a nonmetal react to form a compound, they form ionic bonds to hold together the atoms of the different elements comprising the compound.  

No. an alpha particle is a pair of protons and a pair of neutrons, i.e. a helium

Ibelieve the answer is weathering,hope my answer has you : )