word bank (alphabetical): atoms, chemical reaction, compounds, conversion factor, ions, mole ratio…

word bank (alphabetical): atoms, chemical reaction, compounds, conversion factor, ions, mole ratio, molecules, moles, two substances. when the compared species carry charges, they are classified as like cl⁻. (hint: second example of substances).
Answer
Brief Explanations:
In chemistry, species with charges are called ions. The example given, $Cl^-$, is a negatively - charged ion.
Answer:
ions