1 nm is equal to

• (a) 1 Å
• (b) ${{10}^{-3}}$ mm
• (c) ${{10}^{-9}}$ m
• (d) 100

To determine what 1 nanometer (nm) is equal to, let's break down the options provided and understand the metric system's prefixes. A nanometer is a unit of length in the metric system, specifically in the scale of nanometers, which is one billionth of a meter.

Understanding Nanometers

1 nanometer is defined as:

• 1 nm = 1 x 10^-9 meters

Evaluating the Options

Now, let's analyze each of the options given:

• (a) 1 Å (Angstrom): An angstrom is equal to 0.1 nanometers, so 1 nm is actually 10 Å. This option is incorrect.
• (b) ${{10}^{-3}}$ mm: A millimeter (mm) is 1,000 nanometers, so 1 nm would be ${{10}^{-6}}$ mm, not ${{10}^{-3}}$. This option is also incorrect.
• (c) ${{10}^{-9}}$ m: This is the correct representation of 1 nanometer. It directly states that 1 nm equals 1 billionth of a meter.
• (d) 100: This option does not relate to any metric conversion and is incorrect.

Final Thoughts

Based on the analysis, the correct answer is (c) ${{10}^{-9}}$ m. Understanding these conversions is crucial in fields like physics and chemistry, where measurements at the atomic and molecular levels are common. For example, the size of a typical atom is about 0.1 nm to 0.5 nm, illustrating just how small these measurements are in practical terms.