The screening effect of $d$-electrons is

In a given shell,the order of screening effect is

If $Z_{eff}$ of boron is $x$,then $Z_{eff}$ of oxygen will be

Between $2s$ and $2p$ electrons,which one experiences a greater shielding effect from inner shells?

Which of the following statements is correct about the "shielding effect"?
$1$. It is effective when the orbitals in the inner shells are completely filled.
$2$. Inner shells do not show any effect.
$3$. With an increase of shielding down the group,ionization energy increases.
$4$. With increasing nuclear charge,the shielding effect increases.

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?