The term atomic (Greek: atomos "indivisible") denotes an element, a structure or a state of affairs that cannot be further broken down / subdivided. In contrast to this are the complex / composite structures, which are built up from several sub-components.
In chemistry , atomic means that a chemical element is present in the form of individual atoms, such as noble gases . In contrast, there are molecular elements that can occur as dimers (e.g. oxygen O 2 , nitrogen N 2 , hydrogen H 2 and the halogens F 2 , Cl 2 etc.) or molecules made up of several identical atoms ( phosphorus P 4 ).
In computer science , a process (which can consist of any number of individual pieces) can be described as atomic if it is ensured that it cannot be influenced by other processes that may be running simultaneously . One speaks here of an uninterruptible process. This is achieved either through the use of operations that only require one step (for example through a special machine instruction ), the use of locks or the use of transactions . This is important for the consistency of data, which is why atomicity is a property of the ACID principle.
However, it can also mean a physical process that takes place in the field of atomic physics - i.e. H. physical processes that affect individual atoms and their structure or behavior.