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What is lanthanide contraction?

What is lanthanide contraction?

Grade:12

9 Answers

Boss
102 Points
8 years ago
Lanthanoid contraction, also called lanthanide contraction,  in chemistry, the steady decrease in the size of the atoms and ions of the rare earth elements with increasing atomic number from lanthanum (atomic number 57) through lutetium (atomic number 71). For each consecutive atom the nuclear charge is more positive by one unit, accompanied by a corresponding increase in the number of electrons present in the 4f orbitals surrounding the nucleus. The 4f electrons very imperfectly shield each other from the increased positive charge of the nucleus, so that the effective nuclear charge attracting each electron steadily increases through the lanthanoid elements, resulting ... (100 of 235 words)
 
PRAPULPODISHETTI
669 Points
8 years ago
The gradual decrease in the atomic and ionic sizes of lanthanides with increase in atomic number due to poor shielding effect of 4f-orbitals is called lanthanide contraction Consequences of lanthanide contraction
KUNCHAM SAMPATH
402 Points
8 years ago

Lanthanide contraction is a term used in chemistry to describe the greater-than-expected decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, which results in smaller than otherwise expected ionic radii for the subsequent elements starting with 72, hafnium.[1][2][3] The term was coined by the Norwegian geochemist Victor Goldschmidt in his series "Geochemische Verteilungsgesetze der Elemente".[4]

Element La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Atomic electron configuration
(all begin with [Xe])
5d16s2 4f15d16s2 4f36s2 4f46s2 4f56s2 4f66s2 4f76s2 4f75d16s2 4f96s2 4f106s2 4f116s2 4f126s2 4f136s2 4f146s2 4f145d16s2
Ln3+ electron configuration 4f0 4f1 4f2 4f3 4f4 4f5 4f6 4f7 4f8 4f9 4f10 4f11 4f12 4f13

4f14

Ln3+ radius (pm) (6-coordinate) 103 102 99 98.3 97 95.8 94.7 93.8 92.3 91.2 90.1 89 88 86.8 86.1
SHANMUKESHWAR
461 Points
8 years ago
Lanthanide contraction is a term used in chemistry to describe the greater-than-expected decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, which results in smaller than otherwise expected ionic radii for the subsequent elements starting with 72, hafnium.
santhosh
67 Points
8 years ago
Lanthanide contraction is a term used in chemistry to describe the greater-than-expected decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, which results in smaller than otherwise expected ionic radii for the subsequent elements starting with 72, hafnium.
venky
235 Points
8 years ago
Lanthanide contraction is a term used in chemistry to describe the greater-than-expected decrease in ionic radii of the elements in thelanthanide series from atomic number 57, lanthanum, to 71, lutetium, which results in smaller than otherwise expected ionic radii for the subsequent elements starting with 72, hafnium
SAIMANIKANTA
263 Points
8 years ago
The gradual decrease in the atomic and ionic sizes of lanthanides with increase in atomic number due to poor shielding effect of 4f-orbitals is called lanthanide contraction Consequences of lanthanide contraction
pa1
357 Points
8 years ago

Lanthanide contraction is a term used in chemistry to describe the greater-than-expected decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, which results in smaller than otherwise expected ionic radii for the subsequent elements starting with 72, hafnium.[1][2][3] The term was coined by the Norwegian geochemist Victor Goldschmidt in his series "Geochemische Verteilungsgesetze der Elemente".[4]

Element La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Atomic electron configuration
(all begin with [Xe])
5d16s2 4f15d16s2 4f36s2 4f46s2 4f56s2 4f66s2 4f76s2 4f75d16s2 4f96s2 4f106s2 4f116s2 4f126s2 4f136s2 4f146s2 4f145d16s2
Ln3+ electron configuration 4f0 4f1 4f2 4f3 4f4 4f5 4f6 4f7 4f8 4f9 4f10 4f11 4f12 4f13

4f14

Ln3+ radius (pm) (6-coordinate) 103 102 99 98.3 97 95.8 94.7 93.8 92.3 91.2 90.1 89 88
E.Nandhini ketha
115 Points
6 years ago
The lanthanide contraction is greater than expected decrease in ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, which results in smaller than otherwise expected ionic radii for the subsequent elements starting with 72, hafnium.

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