Final answer:
In chemistry, a number without a unit is considered meaningless. Carbon-12 is the standard reference for this concept.
Step-by-step explanation:
In the field of chemistry, a number without a unit is considered a meaningless measurement. Units give meaning to the numbers we measure and calculate. Carbon-12 is the standard reference for this concept.
For example, if you have a number like 12, it could represent 12 milliliters, 12 liters, or 12 bottles, depending on the units specified. Units are essential in expressing physical quantities accurately.
Without units, numbers can be confusing or even life-threatening. Properly expressing quantities requires both a number and a unit.