Screening effect of inner shells decreases the effective nuclear charge. The order of screening effect of subshells is $s > p > d > f$ . With respect to the above facts, predict the gradation of atomic size in lanthanide elements.

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Solution

Lanthanide contraction:

The steady decrease in size of atoms and ions of rare earth elements with increasing atomic number from lanthanum (Z=57) through lutetium ( Z=71).

Lanthanide contraction is a result of the poor shielding effect of the 4f electrons. Shielding effect is defined as phenomenon by which the inner shell electrons shield the outer shell electrons so that they are not affected by the nuclear charge.

Shielding effect of subshells: s>p>d>f

In lanthanides, f orbitals do shielding. Thus, it's a poor screening effect.

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Similar questions

Q. Screening effect of inner shells decreases the effective nuclear charge. The order of screening effect of subshells is s>p>d>f.
State whether the given statement is true or false.

Ionic radii vary in
(a) inverse proportion to the effective nuclear charge
(b) Inverse proportion to the square of effective nuclear charge
(c) direct proportion to the screening effect
(d) direct proportion to the square of screening effect

Q. The order of screening effect of electrons of

s, p, d

and

f

orbitals of a given shell of an atom on its outer shell electrons is:

The screening effect of electron of s, p, d and f orbitals of a given shell of an atom on its outer shell electrons are in the order of:

If screening effect is not considered, and thus effective nuclear charge is the atomic number then the larger radius out of

L i, N a

is 11.

(consider only atomic number)

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Screening effect of inner shells decreases the effective nuclear charge. The order of screening effect of subshells is s>p>d>f. With respect to the above facts, predict the gradation of atomic size in lanthanide elements.

Screening effect of inner shells decreases the effective nuclear charge. The order of screening effect of subshells is $s > p > d > f$ . With respect to the above facts, predict the gradation of atomic size in lanthanide elements.