Yes, the difference of two whole numbers is always a whole number.
is a natural number a whole number
Always. "Whole number" and "integer" are two different names for the same thing.
No. -3 is a whole number but it is not a natural number.
The atomic nass is not always a whole number, but the atomic number is because its the number of protons and neutrons.
An integer is not always a whole number because whole numbers are numbers 0 and up. Integers are numbers above and below 0. (Including negatives.) So therefore, if an integer is a negative, it would not be a whole number. But a whole number is always an integer.
Whole numbers include the number 0 and counting numbers do not.
An atom can't contain only part of a proton, so the number must always be a whole number
No, only a small minority are whole numbers.
Yes, it is.