The metric unit that we use to measure the volume of a liquid is _______.

degrees
centimeters
grams
newtons
liters

liters

Elements may have isotopes with different ___________ numbers.

mass
ions
atomic
electron
proton

atomic

The metric unit that we use to measure the volume of a liquid is liters.

To determine the answer to this question, you would need prior knowledge of units of measurement or have access to a reliable source such as a textbook or an online resource. In the case of measuring the volume of a liquid, it is common practice to use liters as the unit of measurement in the metric system. Liters are specifically used to measure the capacity or volume of liquids, whereas centimeters, grams, and newtons are commonly used to measure length, mass, and force respectively. Therefore, the correct answer is liters.