Which of the following is the most acidic?

The set of amphoteric oxides among $ZnO$,$Tl_2O_3$,$In_2O_3$,$B_2O_3$,$PbO$,$SnO_2$ is

Among the statements $(I-IV)$,the correct ones are:
$(I)$ $Be$ has smaller atomic radius compared to $Mg$.
$(II)$ $Be$ has higher ionization enthalpy than $Al$.
$(III)$ Charge/radius ratio of $Be$ is greater than that of $Al$.
$(IV)$ Both $Be$ and $Al$ form mainly covalent compounds.

Show by a chemical reaction with water that $Na_{2}O$ is a basic oxide and $Cl_{2}O_{7}$ is an acidic oxide.

The correct set that contains all kinds (basic, acidic, amphoteric, and neutral) of oxides is:

Regarding $F^{-}$ and $Cl^{-}$,which of the following statements is/are correct?
$(i)$ $Cl^{-}$ can give up an electron more easily than $F^{-}$
$(ii)$ $Cl^{-}$ is a better reducing agent than $F^{-}$
$(iii)$ $Cl^{-}$ is smaller in size than $F^{-}$
$(iv)$ $F^{-}$ can be oxidized more readily than $Cl^{-}$