Which of the following metal salts will form a coloured aqueous solution?

Given below are two statements :
Statement $I$ : The higher oxidation states are more stable down the group among transition elements unlike $p-$block elements.
Statement $II$ : Copper can not liberate hydrogen from weak acids.
In the light of the above statements,choose the correct answer from the options given below :

Given below are two statements:
Statement-$I$: The first ionization enthalpy of $Cr$ is lower than that of $Mn$.
Statement-$II$: The second and third ionization enthalpies of $Cr$ are higher than those of $Mn$.
In the light of the above statements,choose the correct answer from the options given below:

$3d^{10}4s^0$ electronic configuration is exhibited by

Which property from the following is $NOT$ exhibited by interstitial compounds?

Among the following metals,the most dense is