Does Empty Set Contain Itself?

The empty set has only one, itself. The empty set is a subset of any other set, but not necessarily an element of it.

Does the empty set contain the empty set?

The empty set is subset of the empty set, as every element of the empty set is an element of the empty set.

What does the empty set contain?

In mathematics, the empty set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero.