Question

What is EFFECTIVE NUCLEAR CHARGE??❓❔

❇also explain it's relationship with Number of Electrons..❇

explain properly...

➕with example ➕

Answer 1

The effective nuclear charge is the net positive charge experienced by an electron in a polyelectronic atom. The term "effective" is used because the shielding effect of negatively charged electrons prevents higher orbital electrons from experiencing the full nuclear charge of the nucleus due to the repelling effect of inner-layer electrons. The effective nuclear charge experienced by the electron is also called the core charge. It is possible to determine the strength of the nuclear charge by the oxidation number of the atom.

Answer 2

HELLO THERE!

Effective nuclear charge is the attractive charge exerted by protons inside the nucleus of an atom, on the valence electrons. And, Nuclear charge refers to the total number of protons present inside the nucleus.

Effective nuclear charge is always less than the nuclear charge (i.e., number of protons), because in this case, shielding effect of electrons come into play.

Shielding effect or screening effect is the phenomenon due to which the electrons present in the subshells screen the valence electrons, so the nuclear pull (effective nuclear charge) on the valence electrons decreases.

The screening power of s > p > d > f.

This means that if s subshell is present close to the nucleus, it will shield the valence electrons strongly (i.e., the effective nuclear charge on the valence electrons will be minimum.

Whereas, if the electrons enter into f subshell (in case of Lanthanides and Actinides), since the screening power of it is minimum, the protons' attractive power on the valence electrons will increase (due to which size decreases, and this is called Lanthanide contraction.)

For the second part of your question, as far as I know, Effective nuclear charge does not depend on the number of electrons present in an atom. Electrons in an s orbital are more effective than those in other orbitals at shielding other electrons from nuclear charge, because shielding power of s orbital is maximum.

An equation says that:

$Z_{eff} = Z - \sigma$

Where Z<eff> is the effective nuclear charge, Z is the nuclear charge (actual number of protons), and б (sigma) is the shielding constant.

This equation proves that the effective nuclear charge is less than the nuclear charge, due to shielding effect. Larger the shielding effect (sigma), smaller is the effective nuclear charge; because the valence electrons, hence, are shielded by the inner electrons.

HOPE MY ANSWER IS SATISFACTORY...

Thanks!