Lanthanide Contraction
| Also Known As | Lanthanide contraction effect, f-block contraction, rare earth contraction |
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What is Lanthanide Contraction?
The lanthanide contraction is the greater-than-expected decrease in atomic and ionic radii across the lanthanide series (Ce to Lu) due to the poor shielding of nuclear charge by 4f electrons. As electrons fill the 4f subshell across the series, the effective nuclear charge increases significantly because f-electrons shield each other poorly. This causes the atom to contract more than expected.
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
The lanthanide contraction is the greater-than-expected decrease in atomic and ionic radii across the lanthanide series (Ce to Lu) due to the poor shielding of nuclear charge by 4f electrons. As electrons fill the 4f subshell across the series, the effective nuclear charge increases significantly because f-electrons shield each other poorly. This causes the atom to contract more than expected.
Explains similar properties of 4d and 5d transition metal pairs. Explains high density of 5d metals (Ir, Os, Pt, W). Affects separation of lanthanides from each other (similar ionic radii). Explains slow increase in basicity of lanthanide hydroxides. Materials science: designing alloys and compounds…
Theoretical concept — no direct safety concerns. Lanthanide compounds vary in toxicity; most are low to moderate hazard.