Down the group what is the effect on Effective nuclear charge and across the period plz explain
Dear Student
Effective nuclear charge is the charge experienced by the valence electrons of an atom taking into account the number of shielding electrons (i.e., electrons in the same atom interacting with each other). The term effective is used because the shielding effect of negatively charged electrons prevents the orbitals from experiencing full nuclear charge. The effective nuclear charge experienced by the valence electrons is always less than the total nuclear charge of an atom.
So, down the group, effective nuclear charge would decrease because of the increasing number of subshells, the shielding effect is high (because atomic radius increases down the group) which more than counters its effect. So, the electrons because loose bounded and it becomes easier to remove them.
Now, across the period, we know the first ionisation energy generally increases. This happens because more protons are now added to the nuclei of the atom, thereby resulting in an increase in their nuclear charge. Therefore, the valence electrons are then more tightly held and it becomes difficult to remove them.
Regards
Effective nuclear charge is the charge experienced by the valence electrons of an atom taking into account the number of shielding electrons (i.e., electrons in the same atom interacting with each other). The term effective is used because the shielding effect of negatively charged electrons prevents the orbitals from experiencing full nuclear charge. The effective nuclear charge experienced by the valence electrons is always less than the total nuclear charge of an atom.
So, down the group, effective nuclear charge would decrease because of the increasing number of subshells, the shielding effect is high (because atomic radius increases down the group) which more than counters its effect. So, the electrons because loose bounded and it becomes easier to remove them.
Now, across the period, we know the first ionisation energy generally increases. This happens because more protons are now added to the nuclei of the atom, thereby resulting in an increase in their nuclear charge. Therefore, the valence electrons are then more tightly held and it becomes difficult to remove them.
Regards