One millionth of a meter is known as what unit?

One millionth of a meter is known as what unit?

• A. Micrometer
• B. Nanometer
• C. Millimeter
• D. Centimeter

Answer: (A)

Understanding metric prefixes and how they scale a base unit is the idea you need here. A meter with the micro- prefix means 10^-6 of a meter, so one millionth of a meter is a micrometer (often written μm). The other prefixes correspond to different powers of ten: nano- is 10^-9 (smaller than a micrometer), milli- is 10^-3 (larger than a micrometer), and centi- is 10^-2 (also larger than a micrometer). So the term for one millionth of a meter is micrometer.

Understanding metric prefixes and how they scale a base unit is the idea you need here. A meter with the micro- prefix means 10^-6 of a meter, so one millionth of a meter is a micrometer (often written μm). The other prefixes correspond to different powers of ten: nano- is 10^-9 (smaller than a micrometer), milli- is 10^-3 (larger than a micrometer), and centi- is 10^-2 (also larger than a micrometer). So the term for one millionth of a meter is micrometer.