Use the localized electron model to describe the bonding in \(\mathrm{H}_{2} \mathrm{O} .\)

To draw the Lewis structure of water (H2O), first count the total number of valence electrons. Oxygen has 6 valence electrons and each hydrogen atom has 1 valence electron. Therefore, H2O has a total of 6 + 1 + 1 = 8 valence electrons. The least electronegative atom, oxygen, is placed in the center. We will now distribute the valence electrons as follows: 1. Place a pair of electrons between each bonded atom (oxygen and hydrogen) to form two single bonds. This accounts for 4 electrons. 2. Complete the octet rule for the central atom (oxygen) by placing the remaining 4 electrons, as lone pairs, around oxygen. The resulting Lewis structure of water is: O / \\ H - O - H | |

To determine the molecular geometry of water, we count both the bonding pairs and lone pairs around the central atom (oxygen). In this case, there are 2 bonding pairs (one for each O-H bond) and 2 lone pairs. According to the VSEPR (Valence Shell Electron Pair Repulsion) theory, the geometry that minimizes the repulsion between these electron pairs is bent, with an angle of about 104.5 degrees between the H-O-H atoms.

The hybridization of the central atom (oxygen) in a molecule can be determined by counting the number of electron domains around the atom. In this case, there are 4 electron domains (2 bonding pairs and 2 lone pairs) around oxygen. This corresponds to an sp^3 hybridization, where the 2s and three 2p orbitals of the oxygen atom combine to form four new, equivalent hybrid orbitals. Each hybrid orbital accommodates a single electron pair (either a bonding or lone pair), resulting in tetrahedral electron geometry with a bent molecular shape due to the lone pairs. In conclusion, the localized electron model describes the bonding in H2O as follows: 1. The Lewis structure features two O-H single bonds and two lone pairs on the central oxygen atom. 2. The resulting molecular geometry is bent, with a bond angle of 104.5 degrees. 3. The hybridization of the central oxygen atom is sp^3, according to the number of electron domains present.