Predict the shape and polarity of each of the following molecules, which have polar covalent bonds: (6.8, 6.9)a. A central atom with three identical bonded atoms and one lone pair.

Valence Shell Electron Pair Repulsion (VSEPR) Theory is a model used to predict the geometry of molecules based on the repulsion between electron pairs around a central atom. According to this theory, electron pairs, including lone pairs and bonding pairs, will arrange themselves to minimize repulsion, leading to specific molecular shapes. For a central atom with three identical bonded atoms and one lone pair, the predicted shape is trigonal pyramidal.

Polarity in molecules arises from the distribution of electrical charge, which is influenced by the presence of polar covalent bonds and the molecular geometry. A molecule is polar if it has a net dipole moment, meaning that the charge distribution is uneven. In the case of a central atom with three identical bonded atoms and one lone pair, the asymmetrical shape leads to a polar molecule due to the unequal sharing of electrons.

Lone pairs are pairs of valence electrons that are not involved in bonding and can significantly affect the shape of a molecule. They occupy space around the central atom and repel bonding pairs, altering the molecular geometry. In the scenario of three bonded atoms and one lone pair, the lone pair's presence distorts the shape from a symmetrical arrangement, resulting in a trigonal pyramidal structure that influences the molecule's overall polarity.