Which of the following statements are correct regarding the elements given below?

${ }_{19}{K}^{39}$, ${ }_{53}{I}^{127}$, ${ }_{17}C{l}^{35}$, ${ }_{35}B{r}^{80}$, ${ }_{18}A{r}^{40}$

I) The correct order of increasing proton number is K, Cl, Br, I, Ar.

II) The correct order of increasing relative atomic mass is Cl, K, Ar, Br, I

III) There is difference in the orders of proton number and relative atomic mass

IV) The number of protons is equal to number of neutrons in all the given elements.