Question

the amount of chemical substances is reported as

Answer 1

 amount of chemical substances is reported as CAS REGISTRY 

Answer 2

A chemical substance [1] , also known as a pure substance , is a form of matter that has constant chemical composition and characteristic properties. [2] It cannot be separated into components by physical separation methods, i.e., without breaking chemical bonds. [3] Chemical substances can be chemical elements , chemical compounds ,
ions or alloys .