• # question_answer $Be{{F}_{2}}$ and ${{H}_{2}}O$ are both tri-atomic molecules but have different shapes. Discuss.

According to VSEPR theory, the geometry and shape of a covalent molecule does not depend upon the number of atoms but on the number of the electron pairs around the central atom. Molecules with different number of such electron pairs are expected to have different shapes. In$Be{{F}_{2}}$, the Be atom is surrounded by two electron pairs while four pairs are present around O atom in ${{H}_{2}}O$. Therefore, they have different shapes.