Electron gain enthalpy α 1Shielding effect (−ve value)
Electron gain enthalpy α 1Shielding effect (−ve value)
The correct option is A True
Atomic size: Think about the shielding effect. What is shielding effect??
Screening or Shielding Effect or Effective Nuclear Charge
Decrease in force of attraction exerted by the nucleus on the valence electron or outermost electron due to the presence of electrons in the inner shells is called screening effect. Screening effect of e- depends on the nature of orbitals e.g.,
s > p > d > f
[with increasing 'l' size of orbital increases and the screening ability decreases]
So the screening effect of f electron is negligible.
Due to screening effect the valence e− experiences less attraction towards nucleus. This brings decrease in the nuclear charge actually present on the nucleus. This reduced nuclear charge is termed as effective nuclear charge. It increases in a period but remain almost same in a group.
The effective nuclear charge can be determined by subtracting a screening constant for the inner electrons from the actual nuclear charge (atomic number). Thus, the effective nuclear charge Zeff experienced by an electrons may be expressed as:
Zeff = Z - σ
Where Z = Nuclear charge (equal to atomic number)
∑ = Shielding constant (screening constant)
Zeffective is real measure of force of attraction exerted on electron by nucleus
herefore,
(c) Screening or Shielding Effect: Electron gain enthalpy value of the elements becomes less negative with the increasing shielding or screening effect. The shielding effect between the outer electrons and the nucleus increases as the number of electrons increases in the inner shells.
Electron gain enthalpy α 1Shielding effect (−ve value)
True
Atomic size: Think about the shielding effect. What is shielding effect??
Screening or Shielding Effect or Effective Nuclear Charge
Decrease in force of attraction exerted by the nucleus on the valence electron or outermost electron due to the presence of electrons in the inner shells is called screening effect. Screening effect of e- depends on the nature of orbitals e.g.,
s > p > d > f
[with increasing 'l' size of orbital increases and the screening ability decreases]
So the screening effect of f electron is negligible.
Due to screening effect the valence e− experiences less attraction towards nucleus. This brings decrease in the nuclear charge actually present on the nucleus. This reduced nuclear charge is termed as effective nuclear charge. It increases in a period but remain almost same in a group.
The effective nuclear charge can be determined by subtracting a screening constant for the inner electrons from the actual nuclear charge (atomic number). Thus, the effective nuclear charge Zeff experienced by an electrons may be expressed as:
Zeff = Z - σ
Where Z = Nuclear charge (equal to atomic number)
∑ = Shielding constant (screening constant)
Zeffective is real measure of force of attraction exerted on electron by nucleus
herefore,
(c) Screening or Shielding Effect: Electron gain enthalpy value of the elements becomes less negative with the increasing shielding or screening effect. The shielding effect between the outer electrons and the nucleus increases as the number of electrons increases in the inner shells.
Electron gain enthalpy α 1Shielding effect (−ve value)
