Which of the following has conductivity and appearance like that of copper metal?

Which pair of elements from the following is used to make an alloy for trophies?

Which one of the following is known as lunar caustic when in fused state?

$A \xrightarrow{4 KOH, O_2} 2 B (Green) + 2 H_2O$
$3 B \xrightarrow{4 HCl} 2 C (Purple) + MnO_2 + 2 H_2O$
$3 C \xrightarrow{H_2O, KI} 2 A + 2 KOH + D$
In the above sequence of reactions,$A$ and $D$,respectively,are:

In a borax bead test under hot condition,a metal salt is heated at point $B$ of the flame,resulting in a green-coloured salt bead. The spin-only magnetic moment value of the salt is $..........$ $BM$ (Nearest integer). [Given atomic number of $Cu=29, Ni=28, Mn=25, Fe=26$]

Potassium manganate $(K_2MnO_4)$ is not formed in which of the following reactions?