JEE Mains · Chemistry · STD 12 - 4. d and f- block elements
Which of the following elements have half-filled \(f\)-orbitals in their ground state ? (Given : atomic number \(Sm =62 ; Eu =63 ; Tb =65 ; Gd =64, Pm =61 \text { ) }\) \(A.\) \(Sm\) \(B.\) \(Eu\) \(C.\) \(Tb\) \(D.\) \(Gd\) \(E.\) \(Pm\) Choose the correct answer from the options given below:
- A \(B\) and \(D\) only
- B \(A\) and \(E\) only
- C \(A\) and \(B\) only
- D \(C\) and \(D\) only
Answer & Solution
Correct Answer
(A) \(B\) and \(D\) only
Step-by-step Solution
Detailed explanation
\(1.\) \({ }_{62} Sm : 4 f ^6 6 s ^2\) \(2.\) \({ }_{64} Gd : 4 f ^7 5 d ^1 6 s ^2\) \(3.\) \({ }_{63} Eu : 4 f^7 6 s ^2\) \(4.\) \({ }_{65} Tb : 4 f ^9 6 s ^2\) \(5.\) \({ }_{61} Pm : 4 f ^5 6 s ^2\)
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
- An organic compound weighing 500 mg , produced 220 mg of \(\mathrm{CO}_2\). on complete combustion. The percentage composition of carbon in the compound is _____ %. (nearest integer)
(Given molar mass in \(\mathrm{g} \mathrm{mol}^{-1}\) of \(\mathrm{C}: 12, \mathrm{O}: 16\))JEE Mains 2025 Medium - Number of complexes which show optical isomerism among the following is _______. \(\operatorname{cis}-\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-},\left[\mathrm{Co}(\mathrm{en})_3\right]^{3+}\) \(\operatorname{cis}-\left[\mathrm{Pt}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{2+}, \text { cis }-\left[\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{+}\) \(\text {trans }-\left[\mathrm{Pt}(\mathrm{en})_2 \mathrm{Cl}_2\right]^{2+}, \text { trans }-\left[\mathrm{Cr}(\mathrm{ox})_2 \mathrm{Cl}_2\right]^{3-}\)JEE Mains 2024 Hard
- The \(IUPAC\) symbols for the element with atomic number \(119\) would be:JEE Mains 2019 Medium
- The group having isoelectronic species is :JEE Mains 2017 Medium
- In which of the following octahedral complex species the magnitude of \({\Delta _0}\) will be maximum ?JEE Mains 2013 Hard
- One mole of \(Cl_{2}\) (g) was passed into 2 L of cold 2M KOH solution. After the reaction, the concentrations of \(Cl^{-}\), \(ClO^{-}\) and \(OH^{-}\) are respectively (assume volume remains constant):JEE Mains 2026 Medium
More PYQs from JEE Mains
- An ideal gas initially at \(0^{\circ} \mathrm{C}\) temperature, is compressed suddenly to one fourth of its volume. If the ratio of specific heat at constant pressure to that at constant volume is \(3 / 2\), the change in temperature due to the thermodynamic process is _____ K.JEE Mains 2025 Medium
- If \(IUPAC \) name of an element is \("unununium"\) then correct statement regarding element isJEE Mains 2024 Hard
- If the sum and product of four positive consecutive terms of a \(G.P.\), are \(126\) and \(1296\), respectively, then the sum of common ratios of all such \(GPs\) is \(.........\).JEE Mains 2023 Hard
- An upright object is placed at a distance of \(40\, cm\) in front of a convergent lens of focal length \(20\, cm\). A convergent mirror of focal length \(10\, cm\) is placed at a distance of \(60\, cm\) on the other side of the lens. The position and size of the final image will beJEE Mains 2019 Hard
- Let \( f(x)=\int\frac{(2-x^{2})e^{x}}{(\sqrt{1+x})(1-x)^{\frac{3}{2}}}dx \). If \( f(0)=0 \), then \( f(\frac{1}{2}) \) is equal to:JEE Mains 2026 Easy
- Given below are two statements :
Statement I : '\( C-Cl \)' bond is stronger in \( CH_{2}=CH-Cl \) than \( CH_{3}-CH_{2}-Cl \)
Statement II : The given optically active molecule
on hydrolysis gives a solution that can rotate the plane polarized light.
In the light of the above statements, choose the correct answer from the options given belowJEE Mains 2026 Medium