Question

4.What is the electron configuration of the element with 27 protons? please me

Answer 1

I put 3 and it wasn't right

Answer 2

Have to start like this

1s^2 2s^2 2^p^6 3s^2 3p^6 4s^2 3d^7

The electronic configuration of cobalt is :1s2 2s2 2p6 3s2 3p6 3d7 4s2
This is so because cobalt has an atomic no of 27. So it will have 27 electrons. The 1st shell can accommodate a maximum of 2 electrons, the 2nd shell can have 8. So that makes it 10, 17

Now the 3s and 3p subshells get filled up with 2 and 6 electrons respectively, but after that instead of the 3d subshell, the 4s subshell gets filled up.(This is so because the 4s subshell has a lower energy level than 3d).

So that makes it 20 electrons. The remaining 7 proceed into the 3d subshell to get a total of 27.

Answer 3

I agree

Answer 4

Thanks