Which metric prefix indicates the smallest part of a unit?

• A. pico-
• B. micro-
• C. nano-
• D. milli-

Answer: (A)

Verified step by step guidance

1. Understand that metric prefixes represent powers of ten that scale a base unit either up or down. Smaller prefixes correspond to smaller fractions of the base unit.
2. Recall the common metric prefixes and their corresponding powers of ten: milli- (\$10^{-3}\(), micro- (\)10^{-6}\(), nano- (\)10^{-9}\(), and pico- (\)10^{-12}$).
3. Compare the powers of ten for each prefix to determine which represents the smallest fraction of the base unit. The more negative the exponent, the smaller the part of the unit.
4. Identify that pico- corresponds to \$10^{-12}\(, which is smaller than nano- (\)10^{-9}\(), micro- (\)10^{-6}\(), and milli- (\)10^{-3}$).
5. Conclude that pico- indicates the smallest part of a unit among the given options.