An "are" (symbol: a) is a unit of area that is not part of the International System of Units (SI) but is used in some countries, particularly in Europe, for measuring land areas. One are is equal to 100 square meters (m²).
To put it simply, 1 are is equivalent to a square with sides that each measure 10 meters. It is a relatively convenient unit for measuring smaller land areas, such as gardens, small fields, or land plots, where using square meters might result in large numbers.
Here are some additional conversions to provide context:
For example, if you have a piece of land that is 5 ares in size, it would be equivalent to 500 square meters (5 ares * 100 m²/are = 500 m²).
The electron cross-section, often referred to as the electron scattering cross-section or simply the electron cross-section, is a term used in the fields of nuclear and particle physics to describe the likelihood of electrons interacting with other particles, such as atomic nuclei or other electrons, when they are subjected to various types of scattering experiments or interactions.
The electron cross-section is typically expressed in units of area, such as square meters (m²) or square femtometers (fm²), and it represents the effective target area presented by an electron for a particular type of interaction or scattering process. It is used to quantify the probability of electron interactions occurring in various experimental setups.