Question

Which of the following factors may be reqrieded as the mean cause of lanthanoid contraction?
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Answer 1

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The filling of if orbits before 5d orbits result regular decrease in atomic radii called Lanthanoid contraction or can say the size of radii not much increase. In lanthanoid contraction shielding of one 4f electron on another 4f electron is less than shielding of one 5d electron on another 5d electron.

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Answer 2

Answer:

Lanthanoid contraction is due to poor sheilding effect of one of 4f electron by another in the subshell.

Explanation:

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