Start with 2 and count up in twos.
Yes. Even numbers greater than 100 is a well defined set. (Although it is a set with an infinite number of members)
Yes.
Yes.
Yes.
Yes, it is closed. This means that if you multiply two even number, you again get a number within the set of even numbers.
The set of integers (ℤ) is the set of the positive whole numbers and their additive opposites (the negative whole numbers).
The set of integers includes the set of whole numbers. The set of rational numbers includes the sets of whole numbers and integers.
Actually the set of integers is the same as the set of whole numbers since the whole numbers include negative whole numbers and zero.
The set of integers is the same as the set of whole numbers.
138 of them.
There is no first since the set of even whole numbers stretch to infinity in both directions. The first non-negative even whole number is 0.
The set of natural numbers is a subset of the set of whole numbers. The set of whole numbers is a subset of the set of integers. So the set of integers is the largest of these three sets.