no
Yes, it is.
False.
No. Rather all natural numbers are necessarily rational number
Yes. The rational numbers are a closed set with respect to subtraction.
Yes, that's true.
No.
Yes. Rational numbers are numbers that can be written as a fraction. Irrational numbers cannot be expressed as a fraction.
No, it is not true.
No. 5 and 2 are real numbers. Their difference, 3, is a rational number.
No, 4/3 is 1.333333... which is not a natural number. However, any natural number divided by a natural number will always be a rational number. This is due to the definition of a rational number as being able to be expressed as p/q where p and q are integers. Thus, numbers where p and q are natural numbers represent a subset of all the rational numbers.
They will always be rational numbers.