Lanthanoid contraction is caused due to

Two p-block elements X and Y form fluorides of the type $\mathrm{EF}_{3}$. The fluoride compound $\mathrm{XF}_{3}$ is a Lewis acid and $\mathrm{YF}_{3}$ is a Lewis base. The hybridizations of the central atoms of $\mathrm{XF}_{3}$ and $\mathrm{YF}_{3}$ respectively are

Elements X and Y belong to Group 15. The difference between the electronegativity values of ' X ' and phosphorus is higher than that of the difference between phosphorus and ' Y '. ' X ' \& ' Y ' are respectively

Identify the correct statements from the following A. $[Fe(C_2O_4)_3]^{3-}$ is the most stable complex among $[Fe(OH)_6]^{3-}$, $[Fe(C_2O_4)_3]^{3-}$ and $[Fe(SCN)_6]^{3-}$ B. The stability of $[Cu(NH_3)_4]^{2+}$ is greater than that of $[Cu(en)_2]^{2+}$ C. The hybridization of Fe in $K_4[Fe(CN)_6]$ is $d^2sp^3$ D. $[Fe(NO_2)_3Cl_3]^{3-}$ exhibits linkage isomerism E. $NO_2^-$ and $SCN^-$ ligands are NOT ambidentate ligands Choose the correct answer from the options given below :

Given below are two statements : Statement I : The number of species among $\mathrm{SF}_{4}, \mathrm{NH}_{4}^{+},\left[\mathrm{NiCl}_{4}\right]^{2-}, \mathrm{XeF}_{4},\left[\mathrm{PtCl}_{4}\right]^{2-}, \mathrm{SeF}_{4}$ and $\left[\mathrm{Ni}(\mathrm{CN})_{4}\right]^{2-}$, that have tetrahedral geometry is 3. Statement II : In the set [$\mathrm{NO}_{2}, \mathrm{BeH}_{2}, \mathrm{BF}_{3}, \mathrm{AlCl}_{3}$], all the molecules have incomplete octet around central atom. In the light of the above statements, choose the correct answer from the options given below :

The correct set that contains all kinds (basic, acidic, amphoteric and neutral) of oxides is: