Question

to convert between g and moles of a substance we use ____.

the molar mass of the substance

avogadros number

the molar ratio

the atomic number of the elements in the substance

Explanation:

To convert between grams (mass) and moles of a substance, we use the molar mass. The formula relating moles ($n$), mass ($m$), and molar mass ($M$) is $n=\frac{m}{M}$. Avogadro's number is used for converting between moles and number of particles. Molar ratio is used in stoichiometric calculations for reactions. Atomic number relates to the number of protons in an atom, not mass - mole conversions. So the correct choice is the molar mass of the substance.

Answer:

the molar mass of the substance