For which of the following is $Z_{eff}$ equal to $Z$?

Explain the relationship between the energy of orbitals in the same subshell and the atomic number,with an example.

Among the following pairs of orbitals,which orbital will experience the larger effective nuclear charge?
$(i)$ $2s$ and $3s$
$(ii)$ $4d$ and $4f$
$(iii)$ $3d$ and $3p$

The bromine atom possesses $35$ electrons. It contains $6$ electrons in $2p$ orbital,$6$ electrons in $3p$ orbital and $5$ electrons in $4p$ orbital. Which of these electrons experiences the lowest effective nuclear charge?

Explain the shielding effect with an example. Also,explain the $2s-2p$ approach in a group and a period.

The unpaired electrons in $Al$ and $Si$ are present in the $3p$ orbital. Which electrons will experience a higher effective nuclear charge from the nucleus?