Given below are two statements: Statement I: The number of species among mathrmSF_4$\mathrm{SF}_4$, mathrmNH_4^+$\mathrm{NH}_4^+$, [mathrmNiCl_4]^2-$[\mathrm{NiCl}_4]^{2-}$, mathrmXeF_4$\mathrm{XeF}_4$, [mathrmPtCl_4]^2-$[\mathrm{PtCl}_4]^{2-}$, mathrmSeF_4$\mathrm{SeF}_4$ and [mathrmNi(CN)_4]^2-$[\mathrm{Ni(CN)}_4]^{2-}$, that have tetrahedral geometry is 3. Statement II: In the set [NO_2, BeH_2, BF_3, AlCl_3]$[NO_{2}, BeH_{2}, BF_{3}, AlCl_{3}]$, 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:

### Core Logic Evaluating Statement I: - mathrmSF_4$\mathrm{SF}_4$: sp^3d$sp^3d$ (1 lone pair) rightarrow$\rightarrow$ See-saw - mathrmXeF_4$\mathrm{XeF}_4$: sp^3d^2$sp^3d^2$ (2 lone pairs) rightarrow$\rightarrow$ Square planar - [mathrmPtCl_4]^2-$[\mathrm{PtCl}_4]^{2-}$: dsp^2$dsp^2$ rightarrow$\rightarrow$ Square planar - [mathrmNiCl_4]^2-$[\mathrm{NiCl}_4]^{2-}$: sp^3$sp^3$ rightarrow$\rightarrow$ Tetrahedral - [mathrmNi(CN)_4]^2-$[\mathrm{Ni(CN)}_4]^{2-}$: dsp^2$dsp^2$ rightarrow$\rightarrow$ Square planar - mathrmSeF_4$\mathrm{SeF}_4$: sp^3d$sp^3d$ (1 lone pair) rightarrow$\rightarrow$ See-saw - mathrmNH_4^+$\mathrm{NH}_4^+$: sp^3$sp^3$ (0 lone pairs) rightarrow$\rightarrow$ Tetrahedral Total tetrahedral species = 2 ([mathrmNiCl_4]^2-$[\mathrm{NiCl}_4]^{2-}$ and mathrmNH_4^+$\mathrm{NH}_4^+$). Statement I says 3, so it is false. Evaluating Statement II: - NO_2$NO_2$: Central N has 7 valence electrons (odd-electron molecule, incomplete octet). - BeH_2$BeH_2$: Central Be has 4 electrons (incomplete octet). - BF_3$BF_3$: Central B has 6 electrons (incomplete octet). - AlCl_3$AlCl_3$ (monomer): Central Al has 6 electrons (incomplete octet). Therefore, all molecules have incomplete octets. Statement II is true. ### Step 1: Final Conclusion Statement I is false, Statement II is true. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Chemical Bonding and Molecular Structure Class 12 Chemistry: Coordination Compounds