Question

How does the molecular geometry of water affect its properties?

Answer 1

The three-dimensional arrangement of the atoms that make up a molecule is known as molecular geometry. It comprises the molecule's overall form, as well as bond lengths, bond angles, torsional angles, and any other geometrical factors that define each atom's location.

Complete answer:
The reactivity, polarity, phase of matter, colour, magnetism, and biological activity of a material are all influenced by molecular geometry. The angles between bonds formed by one atom are only weakly dependent on the rest of the molecule, thus they may be thought of as roughly local and hence transferrable characteristics.
A polar molecule is water (i.e. it has a dipole moment.) Water has more electronegative oxygen than hydrogen. As a result, it attracts the bonding electrons to itself. This gives Oxygen a partial negative charge while giving Hydrogen a partial positive charge. Any polar molecule can do this. Water, on the other hand, does not end there. Hydrogen bonds are weak connections between water molecules that occur when they are in close proximity. One water molecule's partially negatively charged Oxygen interacts with another's partially positively charged Hydrogen.
While these individual links aren't nearly as strong as actual bonds, when they're combined, they give water all of its unique properties. The number of atoms in a molecule and the angles between their bonds determine the geometry of the molecule. The molecules $C{{O}_{2}}$ and ${{H}_{2}}O$ , for example, both have three atoms. Carbon dioxide has a $180{}^\circ$ angle between its bonds, making it a linear molecule. Water is a bent molecule because the angle between its bonds is $104.5{}^\circ$ .
Molecule shapes have significant effects. One is that, despite the presence of dipoles in both $C=O$ and $O-H$ bonds, carbon dioxide molecules are nonpolar owing to their linear structure, but water molecules are polar due to their bent shape.
Water's polarity implies that it can form hydrogen bonds, has a high surface tension, and is an excellent solvent.

Note:
The tetrahedral geometry of the water molecule is deformed. The electrons in the O atom are divided into two lone pairs and two bond pairs. The $s{{p}^{3}}$ hybridisation of the O atom results in a tetrahedral shape. The $H-O-H$ bond angle is somewhat smaller than the tetrahedral bond angle of ${{108}^{o}}$ due to lone-pair lone-pair, lone-pair bond-pair, and bond-pair bond-pair repulsions.