Definition
Prime
Prime Attribute
An attribute is called prime if it is contained by any key candidate. Conversely, an attribute is called non-prime if is is not part of any key candidate.
Atomicity
Atomicity does not necessarily mean that attribute which are divisible must be divided at any cost. For example, a date is already atomic whereby it can be divided into day, month and year. The same applies for values, such as addresses. If not necessary due to business rules, the address must not be divided into smaller atomic values.