Answer:
[Ar] 3d10 4s1
Step-by-step explanation:
The correct electronic configuration of copper is [Ar] 3d10 4s1
Copper has atomic number 29 and due to the stability of half filled or fully filled orbitals or shells, the electrons from the 4s jumps to the 3d and makes the 3d shell contain 10 electrons.
This is what I mean:
Cu = Ar 4s2 3d10 is the expected configuration of copper when we follow the principle of filling the various orbitals that is the s, p, d, f orbitals.
But because we write 3d before writing 4s, we have Ar 3d10 4s2. Instead of this configuration becoming the correct one, an electron from the 4s orbital jumps to the 3d orbital to complete the orbital giving the electrons in the 3d orbital 10.
So therefore the correct configuration is Ar 3d10 4s1