Question

If Aufbau rule is not followed, $K-19$ will be placed in .................... block.

• A. $s$
• B. $p$
• C. $d$
• D. $f$

Answer 1

Answer: (C)

$d$

$K$ has atomic no $19$ so it has total $19$ll be:
$1s^{2}2s^{2}2p^{6}3s^{2}3p^6\frac{3d^1}{\uparrow }$
last-filling electron goes into d-orbital.
so it will belong to d-block elements.