wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Why the atomic radii of the second and third transition series are almost same?

A
Actinoid contraction
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
Radioactive nature
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Lanthanoid contraction
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
Filled d-orbital
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C Lanthanoid contraction
In elements of second transition series, the number of shells increases compared to first transition series so, their atomic radii is greater than that of the first transition series. The atomic radii of the second and third transition series are almost same due to lanthanoid contraction.
Lanthanoid contraction is the imperfect shielding of one electron by another in the same set of orbitals.

The filling of 4f before 5d orbital results in a regular decrease in atomic radii because f orbitals have very poor shielding effect which leads to higher nuclear attraction on outermost electrons. Also the drastic increase in positive nuclear charge from 4d to 5d increase its attraction toward the electrons.

flag
Suggest Corrections
thumbs-up
14
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Ionization Enthalpy
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon