Question

acc to afbau's principal 3d has more energy than 4s... but in electronic configuration... like of zinc its written
${ar}\: 3d {}^{10} 4s {}^{2}$
so if 4s<3d.. then why 3d shell has come first?​

Answer 1

$\huge\text{\underline{Answer}}$$\sf{\underline{Step by step explanation}}$

Your questions is right ✔️

but in case of electriconic configurations of an elements the 3d is placed because the shell number is less than 4s.

in case of zinc the 3d is written before because the shell number is less than 4s and shell number is arranged in order not in increasing order of energy level.

In every electronic configuration first we should write the configuration according to increasing energy level then we have to arrange it according to the shell number. And least shell number is written before the maximum shell number.

Answer 2

hi

phipool

I want yo become friends