Lanthanides: electronic configuration, lanthanide contraction
f-Block Elements · Chemistry
Study notes
Zr and Hf have nearly identical atomic radii (160 pm). Explain. Step 1: Hf comes after the lanthanides; Zr comes before. Step 2: Lanthanide contraction shrinks the 4f-filled atoms by ~17 pm. Step 3: This cancels the expected size increase from period 5 to 6. Step 4: Result: Zr and Hf are 'chemical twins' — nearly inseparable, found together in ores!