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. a mole ratio can compare individual such as hydrogen, h (hint: look at the first example of substances).
Answer
Brief Explanations:
A mole ratio compares amounts of substances in a chemical - related context. The substances can be elements like hydrogen. Elements are made up of atoms. In the word bank, atoms is the most appropriate term as a mole ratio can compare individual atoms.
Answer:
atoms