Nanometres
Introduction
A nanometre (nm) is a unit of length in the metric system, equal to one billionth of a meter. It is often used in the fields of science and technology, particularly in nanotechnology, physics, chemistry, and biology.
Definition and Measurement
The nanometre is derived from the Greek word 'nanos', meaning 'dwarf', and the French word 'metre', meaning 'measure'. It is a unit of length in the metric system, which is based on powers of ten. One nanometre is equal to one billionth of a metre, or 10^-9 metres. This makes it one of the smallest units of measurement that is commonly used in scientific research and technology development.
The size of objects measured in nanometres ranges from atomic to molecular scale. For instance, a single gold atom is approximately one third of a nanometre in diameter, while a DNA double-helix has a diameter of about 2 nanometres.
Uses of Nanometres
Nanometres are used in a variety of scientific and technological fields. They are particularly important in nanotechnology, where they are used to measure the size of nanoparticles and other nanoscale objects.
In physics, nanometres are used to measure the wavelength of light and other electromagnetic waves. For example, visible light has wavelengths ranging from about 400 to 700 nanometres.
In chemistry, nanometres are used to measure the size of molecules and atoms. For instance, a water molecule is about 0.3 nanometres in diameter.
In biology, nanometres are used to measure the size of biological structures, such as proteins and viruses. For example, the influenza virus is about 100 nanometres in diameter.
In technology, nanometres are used to measure the size of components in electronic devices, such as transistors in computer chips. For example, as of 2020, the most advanced computer chips have transistors that are just 5 nanometres wide.
Nanometre-Scale Science and Technology
The nanometre scale is of particular interest in science and technology because it is at this scale that the properties of materials can change dramatically. For instance, nanoparticles of gold are red in colour, unlike bulk gold which is yellow. This is because the small size of the particles affects the way they interact with light.
In technology, the ability to manufacture and manipulate materials at the nanometre scale has led to the development of nanotechnology, a field that has the potential to revolutionize many areas of life, from medicine to energy production.