NEET · Chemistry · STD 12 - 4. d and f- block elements
Reason of lanthanoid contraction is
- A negligible screening effect of \('f'-\)orbitals
- B increasing nuclear charge
- C decreasing nuclear charge
- D decreasing screening effect.
Answer & Solution
Correct Answer
(A) negligible screening effect of \('f'-\)orbitals
Step-by-step Solution
Detailed explanation
Lanthanoid contraction is the regular decrease in atomic and ionic radii of lanthanides. This is due to the imperfect shielding [or poor screening effect ] of \(l-\)orbitals due to their diffused shape which unable to counterbalance the effect to the increased nuclear charge. Hence, the net result is a contraction in size of lanthanoids.
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- In the following reaction: \(HC \equiv CH\,\xrightarrow[{H{g^{2 + }}}]{{{H_2}S{O_4}}}\,'P'\) Product \('P'\) will not giveNEET 2013 Medium
- During Lassaigne's test, the elements present in an organic compound are converted from :NEET 2026 Easy
- Consider the reaction, \(CH_3CH_2CH_2Br + NaCN \to \)\(CH_3CH_2CH_2CN+ NaBr\) This reaction will be the fastest inNEET 2016 Hard
- The liquified gas that is used in dry cleaning along with a suitable detergent isNEET 2019 Medium
- The calculated spin only magnetic moment of \(Cr ^{2+}\) lon is......\(\, B.M.\)NEET 2020 Easy
- How many products (including stereoisomers) are expected from monochlorination of the following compound?
NEET 2025 Hard
More PYQs from NEET
- Smooth muscles areNEET 2016 Medium
- If there are \(999\) bases in an \(RNA\) that code for a protein with \(333\) amino acids, and the base at position \(901\) is deleted such that the length of the \(RNA\) becomes \(998\) bases, how many codons will be altered?NEET 2017 Medium
- In a gravitational field, the gravitational potential is given by, \(V =-\frac{ K }{ x }( J / kg )\). The gravitational field intensity at point \((2,0,3)\,m\) isNEET 2022 Medium
- In photosynthesis, the lightindependent reactions take place atNEET 2015 Medium
- Two particles \(A\) and \(B\) are moving in uniform circular motion in concentric cirdes of radius \(r_{A}\) and \(r_{B}\) with speed \(v_A\) and \(v_B\) respectively. The time period of rotation is the same. The ratio of angular speed of \(A\) to that of \(B\) will beNEET 2019 Medium
- The type of conservation in which the threatened species are taken out from their natural habitat and placed in special setting where they can be protected and given special care is calledNEET 2024 Medium