Question

If Aufbau and Hund's rule are not used, then incorrect statement is:

• A. $K^{+}$ would be coloured ion
• B. $Na$ will be in s-block (if these rules are true)
• C. $Cu$ would be s-block element
• D. magnetic moment of $Cr\left(24\right)$ would be zero

Answer 1

The correct option is A $K^{+}$ would be coloured ion

K(19) $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^1$
$K^{+}\left(19\right)1s^{2}2s^{2}2p^{6}3s^{2}3p^6$
colourless being no unpaird electron in d-orbital
Na(11) $1s^{2}2s^{2}2p^{6}3s^1$ s-block - true
Cu(29) $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^1$ s-block - true
Cr(24) $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^6$ true