Final answer:
Medical professionals use 'mL' for milliliters instead of 'cc' to follow standardized metric system conventions, where the liter is abbreviated as 'L' and not as '1' to avoid confusion, maintaining consistency across different units of measurement.
Step-by-step explanation:
Medical professionals often use the abbreviation mL instead of cc (cubic centimeter) despite both units being equivalent in volume because mL follows the conventional formatting of metric units. Most metric abbreviations, such as 'm' for meter, are lowercase; however, for volume, the base unit 'liter' is represented as 'L' to distinguish it from the number '1'. Therefore, a volume of 3.5 milliliters should be correctly written as 3.5 mL.
The use of mL is widespread in the medical community to maintain consistency with other metric units. Additionally, 1 milliliter is defined as the volume of a cube that measures 1 cm on each side, reinforcing that 1 mL is indeed equal to 1 cubic centimeter (1 cm³).