Question

The set which does not contain any element is called

Answer 1

Answer:

The set which does not contain any element is called an empty set, or the null set or the void set .

Answer 2

In mathematics, the empty set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero.[1][2] Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set, while in other theories, its existence can be deduced. Many possible properties of sets are vacuously true for the empty set. In some textbooks and popularizations, the empty set is referred to as the "null set".

null set- In mathematical analysis, a null set  is a measurable set that has                           measure zero. This can be characterized as a set that can be covered by a countable union of intervals of arbitrarily small total length