A molecule with the formula mathrmAX_4mathrmY$\mathrm{AX}_4\mathrm{Y}$ has all its elements from p-block. Element A is rarest, monoatomic, non-radioactive from its group and has the lowest ionization enthalpy value among A, X and Y. Elements X and Y have first and second highest electronegativity values respectively among all the known elements. The shape of the molecule is :

### Core Logic Analyzing the hybridization of the central atom in each species: - NH_3$NH_3$: 3 bp + 1 lp = 4 electron domains rightarrow sp^3$\rightarrow sp^3$ - SO_2$SO_2$: 2 bp + 1 lp = 3 electron domains rightarrow sp^2$\rightarrow sp^2$ - SiO_2$SiO_2$: A giant covalent network where each Si is bonded to 4 oxygens tetrahedrally rightarrow sp^3$\rightarrow sp^3$ - BeCl_2$BeCl_2$: 2 bp + 0 lp = 2 electron domains rightarrow sp$\rightarrow sp$ - CO_2$CO_2$: 2 bp + 0 lp = 2 electron domains rightarrow sp$\rightarrow sp$ - H_2O$H_2O$: 2 bp + 2 lp = 4 electron domains rightarrow sp^3$\rightarrow sp^3$ - CH_4$CH_4$: 4 bp + 0 lp = 4 electron domains rightarrow sp^3$\rightarrow sp^3$ - BF_3$BF_3$: 3 bp + 0 lp = 3 electron domains rightarrow sp^2$\rightarrow sp^2$ Total species with sp^3$sp^3$ hybridization: NH_3, SiO_2, H_2O, CH_4$NH_3, SiO_2, H_2O, CH_4$. Total count = 4. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Chemical Bonding and Molecular Structure