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

${}_{19}{}^{39} \mathrm{K}, {}_{53}{}^{127}\mathrm{I}, {}_{17}{}^{35}\mathrm{Cl}, {}_{35}{}^{80}\mathrm{Br}, {}_{18}{}^{40}\mathrm{Ar}$

I The correct order of increasing proton number is $\mathrm{K}<\mathrm{Cl}<\mathrm{Br}<\mathrm{I}<\mathrm{Ar}$
II The correct order of increasing mass number is $\mathrm{Cl}<\mathrm{K}<\mathrm{Ar}<\mathrm{Br}<\mathrm{I}$
III There is difference in the orders of proton number and mass number.
IV The number of protons is equal to number of neutrons in all the given elements.

Identify the difference between particles of each given pair.

(I)  ${}^6\mathrm{Li}$ and ${}^7\mathrm{Li}$
(II)  ${}^{32} \mathrm{S}$ and ${{}^{32} \mathrm{S}}^{2-}$
(III)  ${{}^{39} \mathrm{K}}^{+}$ and ${{}^{40}\mathrm{Ca}}^{2+}$

Which of the given pairs of atoms contain(s) the same number of neutrons?

I ${}_{48}{}^{114}\mathrm{Cd}$ and ${}_{50}{}^{119}\mathrm{Sn}$

II ${}_{27}{}^{59}\mathrm{Co}$ and ${}_{28}{}^{59}\mathrm{Ni}$

III ${}_{55}{}^{133}\mathrm{Cs}$ and ${}_{54}{}^{132}\mathrm{Xe}$

IV ${}_{29}{}^{63}\mathrm{Cu}$ and ${}_{29}{}^{65}\mathrm{Cu}$

Description of a few atoms is given in the table.

Identify a cation, an anion and a pair of isotopes from the given table:

Study the given mass spectrum of magnesium carefully.

The number of protons in ${}^{26}\mathrm{Mg}$, number of neutrons in ${}^{25}\mathrm{Mg}$, and the relative atomic mass of $\mathrm{Mg}$ are respectively

Electron distribution of two elements $P$ and $Q$ in their outermost shell is shown below.

Atomic numbers of $P$ and $Q$ are respectively