Which of the following oxides is white but becomes yellow on heating?

The general electronic configuration of transition elements is

The electronic configuration of a metal element is given below:
$M = 1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$
To which block does this element belong?

Match the following:

List-$I$ (Element)	List-$II$ (Block)
$(A)$ $Ra$	$(I)$ $p$-block
$(B)$ $Uuq$	$(II)$ $s$-block
$(C)$ $Ds$	$(III)$ $f$-block
$(D)$ $Fm$	$(IV)$ $d$-block

The correct answer is

The magnetic moments for $Ti^{2+}$,$V^{3+}$,and $Ni^{2+}$ are respectively:

Identify the outer electronic configuration of the $first$ element of the $first$ transition series.