Chemistry > Periodic Table > 4.0 Size and type of bonding in atoms.
Periodic Table
1.0 Introduction
2.0 Modern Periodic Law & Modern Periodic Table
3.0 s,p,d,f Block Elements
4.0 Size and type of bonding in atoms.
5.0 Ionization Potential
5.1 Factor Affecting Ionization Potential
5.2 Trends in Ionization Potential
5.3 Ionization Potential of Transition Elements
5.4 Application of Ionization Potential
6.0 Electron Affinity
7.0 Electronegativity
4.1 Effective Nuclear Charge
5.2 Trends in Ionization Potential
5.3 Ionization Potential of Transition Elements
5.4 Application of Ionization Potential
- In a polyelectronic atom, the internal electrons repel the electrons of the outermost orbit. This results in the decrease in the nuclear attraction on the electrons of the outermost orbit.
- Therefore, only a part of the nuclear charge is effective on the electrons of the outermost orbit. Thus, the inner electrons protect or shield the nucleus and thereby decrease the effect of nuclear charge towards the electrons of the outermost orbit.
- Thus the part of the nuclear charge works against outer electrons is known as effective nuclear charge.
${Z^*} = Z - \sigma $
where,
Z^* = effective nuclear charge,
s = shielding constant
Z = nuclear charge
- A scientist named Slater, determined the value of shielding constant and put forward some rules as following,
- The shielding effect or screening effect of each electron of 1 s orbital is 0.30.
- The shielding effect of each electron of ns and np i.e. electron of the outermost orbit is 0.35.
- The shielding effect of each electron of s,p or d orbitals of the penultimate orbit (n-1) is 0.85.
- The shielding effect of each electron of s, p, d or f orbital of the inner-penultimate orbit (n-2) and below is 1.0.
