Question

For the element with atomic number 27.Write the electronic configuration.
1) Write down the value of n and l for the electrons in the valence
shell.
2)How many unpaired electrons are present in it.

Answer 1

configuration is $\left[Ar\right]3d^{7}4s^2$

Valence shell is $3d^7$

the value of n is 3

so the value of l varies 0 to 2 but for valence shell electrons value of l is 2

All subshells are full filled except $3d^7$ and there are 7 electrons present in $3d^7$ so 2 electrons are unpaired.