Elements $A$ and $B$ do not form an alloy because....

Among $Fe^{2+}$, $Fe^{3+}$, $Cr^{2+}$ and $Zn^{2+}$, the ion that shows positive borax bead test and with highest ionisation enthalpy is:

An element of atomic number $29$ belongs to

Which of the following is the correct sequence of atomic weights of the given elements?

Among the following pairs of ions,the lower oxidation state in aqueous solution is more stable than the other in:

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 :