Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

What is measured by a nanometer?

1. Weight

2. Specific gravity

3. Length

4. Density

The correct answer is: Length

A nanometer is a unit of measurement in the metric system that denotes a length equivalent to one billionth of a meter (1 nm = 10^-9 meters). It is commonly used in scientific disciplines, particularly in fields such as nanotechnology, physics, and chemistry, to measure extremely small dimensions, such as the wavelength of light, the size of atoms and molecules, and the dimensions of nanoparticles. The other options relate to different physical quantities. Weight is a measure of the force exerted on an object due to gravity and is typically measured in units like grams or pounds. Specific gravity is a dimensionless number that compares the density of a substance to the density of water. Density is a measure of mass per unit volume, generally expressed in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³). Each of these measures quantifies different characteristics of matter, whereas a nanometer specifically quantifies length.