Most people are familiar with measuring objects and distances with units such as centimeters, meters, and kilometers. Centimeters can show how long a smaller object is, meters can measure larger objects and short distances, whilst kilometers are used to measure long distances.
However, there are some materials and substances that are too small to measure using an everyday unit of measurement. Some matter, such as atoms and molecules, need specialist equipment to show their size as they are too small to see with the naked eye.
To help them measure incredibly small dimensions, scientists use a type of spatial measurement called a nanometer. This unit of measurement is frequently used in nanotechnology, which is a relatively modern area of study.
In this article, we'll look at what a nanometer is and the types of materials and objects it can measure.
A nanometer (nm) is an official unit of length in the International System of Units. It was formerly called 'millimicrometre', as it was 0.001 of a micron. One nanometer equals one billionth of a meter (1x10-9) and is typically expressed as 1×10⁻9m.
To put the size of nanometers into perspective, a single sheet of paper is around 100,000 nanometers thick. In addition, the diameter of the Earth would measure about one meter if the diameter of a marble measured one nanometer. Your fingernail also grows approximately one nanometer per second.
This form of measurement was first proposed in 1914 by Austrian chemist Richard Zsigmondy. The idea was to have a way of measuring particles under a microscope. Nanotechnology, where nanometers are predominately used as a form of measurement, was introduced as a concept by American physicist Richard Feynman in 1959.
Molecules and atoms are typically expressed in nanometers, as are wavelengths of high frequencies on the electromagnetic spectrum and visible light wavelengths.
0.1 nanometers is equal to one Ångström (10-10 m). An Ångström is a unit of measurement that is frequently used in chemistry and physics. However, it isn't an official SI unit of measurement as the nanometer is. The two units are close in size, which means that they are often used to measure the same substances and objects. The International System of Units favored the nanometer because it measures in groups of 10 rather than three (as the Ångstrom unit does).
Nanometers are used in nanotechnology to measure small machines and parts, such as electronic components. Atoms and molecules are small enough that they can only be measured with small units of measurement, like nanometers. Nanometers are typically used to measure the wavelength of ultraviolet and visible light.
Visible light wavelengths measure between 400 to 780 nanometers and don't interact with materials or objects that are smaller than -300 nanometers. The size of a wavelength will change the color of the visible light. There are seven colors in total, as listed below:
- Violet - shortest wavelength (between 400 to 420 nm)
- Indigo - 420 to 440 nm
- Blue - 440 to 490 nm
- Green - 490 to 570 nm
- Yellow - 570 to 585 nm
- Orange - 585 to 620 nm
- Red - longest wavelength (between 620 to 780 nm)
How big is an atom in nanometers?
Atoms typically have a radius that measures between 0.1 and 0.5 nanometers. 10 hydrogen atoms approximately equal one nanometer. One atom is equal to one Ångström, which is another unit of measurement that is used to measure atoms.
The diameter of an atom measures an estimated 1×10 -10m, while the nucleus of an atom measures approximately 10-15 m.
How big is a water molecule in nanometers?
A water molecule measures approximately 0.27 nanometers in length. Water molecules are smaller than most other types of molecules. They are made up of two hydrogen atoms and one oxygen atom, which means that all water molecules have the same shape because the atoms are bonded at the same angle.
How big is a human hair in nanometers?
A single strand of hair has a diameter of approximately 80,000 to 100,000 nanometers, which equals an estimated 100 micrometers. The thickness of hair can vary depending on the individual. Some individuals with thinner hair may have hair strands that are around 50,000 nanometers thick.
How big is a DNA strand in nanometers?
Deoxyribonucleic acid (DNA) consists of two polynucleotide chains that are joined to create a double helix. A single DNA strand measures an estimated two nanometers in width. This is approximately 40,000 times thinner than a single human hair.
A cell of DNA would measure around two meters if you were to stretch them out in a line. The entirety of your DNA in all your cells would measure twice the length of the Solar System if you were to stretch them out in a row.
How big is a bacterium in nanometers?
On average, bacteria measure between 1,000 to 3,000 nanometers. This is larger than viruses, which measure anywhere between 10 to 100 nanometers. A virus is the smallest reproducing organism.
Nanometers are one-billionth of a meter, which is a measurement used in the metric system. The metric system has been adopted worldwide, except for a small number of countries, such as the United States.
Although the US doesn't typically use metric units, nanometers are frequently used by individuals working in STEM. This is because the imperial system and US customary measurement system were created before there was a need or technology to measure extremely small objects and microscopic components.
There may be instances that you want to convert nanometers into other unit measurements or vice versa. To do so, you will need to divide the number of nanometers by the conversion rate listed in the table below.
To convert nanometers into meters, you need to multiply the nanometers by 0.000000001 (1x10-9). Alternatively, you can divide the number of nanometers by 1,000,000,000 (1x109).
The table below shows the conversion rate between standard metric, imperial, and US customary units to nanometers.
| Unit | Conversion to nanometers |
| 1 kilometer (km) | 1,000,000,000,000 |
| 1 meter (m) | 1,000,000,000 |
| 1 centimeter (cm) | 10,000,000 |
| 1 millimeter (mm) | 1,000,000 |
| 1 micrometer (μm) | 1,000 |
| 1 mile (mi) | 1,609,350,000,000 |
| 1 yard (yd) | 914,400,000 |
| 1 foot (ft) | 304,800,000 |
| 1 inch (in or ') | 25,400,000 |
A nanometer is a unit used to measure length. It is typically used to calculate the length of atomic structures and other components that are extremely small. The wavelengths of visible light are also commonly measured in nanometers.
One nanometer is the equivalent of one billionth of a meter. The small scale of this unit of measurement means that it is most commonly used in STEM areas rather than in everyday life.
