Which of the following factor may be regarded as the main cause of lanthanide contraction?
A. Poor shielding of one of the 4f-electrons by another in the subshell.
B. Effective shielding of one of the 4f-electrons by another in the subshell.
C. Poorer shielding of 5d electrons by 4f electrons.
D. Greater shielding of 5d electrons by 4f electrons.
Answer:A
Which of the following factor may be regarded as the main cause of lanthanide contraction?
A. Poor shielding of one of the 4f-electrons by another in the subshell. B. Effective shielding of one of the 4f-electrons by another in the subshell. C. Poorer shielding of 5d electrons by 4f electrons. D. Greater shielding of 5d electrons by 4f electrons.