Final answer:
The valid conversion factors from the options provided are 1,000ml/1L, because 1 L is equal to 1,000 mL, and 1,000cg/1g, because 1 g is equal to 1,000 cg.
Step-by-step explanation:
The question is asking which of the listed ratios is a valid conversion factor for units of measure. A conversion factor is a ratio that is used to convert from one unit to another without changing the value of the quantity. From the given options:
- 1,000ml/1L is a valid conversion factor because 1 liter (1 L) is equal to 1,000 milliliters (1,000 mL).
- 1hm/1,000m is not valid because 1 hectometer (1 hm) is equivalent to 100 meters, not 1,000 meters.
- 1 cm³/1 L is not valid because 1 liter is equal to 1,000 cubic centimeters (1,000 cm³), not 1 cm³.
- 1,000cg/1g is valid because 1 gram (1 g) is equal to 1,000 centigrams (1,000 cg).
Therefore, the valid conversion factors from the options provided are 1,000ml/1L and 1,000cg/1g.