Question

4s1 3d5 is the valency electronic configuration of​

Answer 1

[Ar] 4s¹ 3d⁵ is the valence electronic for Chromium.

Let's learn a few facts about this peculiar electronic configuration:

• Atomic number of Chromium is 24

• So, the expected electronic configuration should have been as follows:

Cr(24) : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁴

• We can also expect it as follows:

Cr(24) : [Ar] 4s² 3d⁴

• However, we don't get the above electronic arrangement because when the "d" orbital becomes half filled with electrons (d⁵ condition), the atom gains stability.

• Thats why 1 electron from 4s orbital goes to 3d to make 3d⁵ configuration.

• Hence, the actual configuration is as follows:

Cr(24) : 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵

• Kindly remember this peculiarity, it is often asked in exams.

$\star$ Hope It Helps.

Answer 2

HELLO DEAR,

4s1 3d5 is the electronic configuration ot transition elements ( ground state ) of Cr.

Its an special care about the electronic configuration of Cr in 4s 3d .

Also Cu have electronic configuration of 4s1 3d10 is also an special case in 4s 3d series .

it is a condition due to the half filled d orbital and fulfill d orbital electronic configuration in transition element.

So at the exam point of views we have to remember that two are special case in electronic configuration of transition element.

I HOPE IT'S HELP YOU DEAR,

THANKS.