The element with atomic number $23$ is placed in the periodic table in:

The electronic configuration of silver atom in ground state is

What is the name of the element with atomic number $105$?

$A$ copper coin was electroplated with $Zn$ and then heated at high temperature until there is a change in colour. What will be the resulting colour?

In the $3d$ series,the metal having the highest $M^{2+}/M$ standard electrode potential is .... .

Copper exhibits only $+2$ oxidation state in its stable compounds. Why?