Final answer:
A nanometer is one billionth of a meter, symbolized as 1 nm = 10^(-9) m. It is a unit of length used in the metric system for measuring extremely small distances, such as molecular and atomic scales.
Step-by-step explanation:
A nanometer is a unit of length in the metric system and is equivalent to one billionth of a meter. This can be mathematically represented as 1 nanometer (nm) = 10^(-9) meters (m). In scientific notation, this relationship is sometimes expressed as 1 m = 10^9 nm, establishing the conversion factor between meters and nanometers.
The metric system is based on powers of ten, which means that each unit is either ten times larger or smaller than the next. For instance, a kilometer (km), which is 1,000 meters, is three orders of magnitude larger than a meter, while a nanometer is nine orders of magnitude smaller than a meter.
To visualize the scale of a nanometer, consider that a human hair is approximately 80,000 to 100,000 nanometers in diameter. This puts into perspective how incredibly small a nanometer is. Therefore, nanometers are often used to measure things at the molecular or atomic level, such as the wavelengths of ultraviolet light, the size of molecules, or the gate length on a computer chip.
In the context of this question, the correct answer to 'A nanometer is:' is d. One billionth of a meter. It is essential to understand these units and their conversions for various scientific and engineering applications, especially in fields like nanotechnology, physics, and chemistry.
Other related units that were mentioned, such as micrometers, millimeters, centimeters, etc., represent different scales and are also based on the metric system, with each having a specific place and use depending on what is being measured. Students must grasp these concepts to gain an intuitive understanding of measurement scales.