a sample of matter breaks down into two kinds of atoms. Was the original sample an element or a compound?

Answer :

The original sample was an compound, as an element would simply just not break down as it’s composed by itself.

Answer:

element

Explanation:

Matter can be broken down into two categories: pure substances and mixtures. Pure substances are further broken down into elements and compounds. A chemical substance is composed of one type of atom or molecule. A mixture is composed of different types of atoms or molecules that are not chemically bonded.