Which one of the following is not a transition metal?

The correct set of ions (aqueous solution) with the same colour from the following is:

Identify the order in which the spin-only magnetic moment (in $BM$) increases for the following four ions:
$(I) Fe^{2+}$
$(II) Ti^{2+}$
$(III) Cu^{2+}$
$(IV) V^{2+}$

The $d-$block element which is a liquid at room temperature,has a high specific heat,lower reactivity than hydrogen,and its chloride $(MX_2)$ is volatile on heating is

What should be the difference in atomic radii between two metal elements to form an alloy?

Among the following series of transition metal ions,the one where all metal ions have $3d^2$ electronic configuration is