This type of clothing should not be worn for parties, weddings and other formal or ceremonial events. They should not also be worn for work. Various items of clothing such as tee-shirts, denims, khakis, jackets, hoodies, mini-skirts, summer dresses, loafers, sneakers, and sandals are casual wear.
The presence of a lone pair decreases the bond angle between the bonding pair of electrons, due to their high electric charge which causes great repulsion between the electrons. They are also used in the formation of a dative bond.
A lone pair on the oxygen atom in water contributes two electrons to form a coordinate covalent bond with a hydrogen ion to form the hydronium ion. Similarly, a lone pair on nitrogen contributes 2 electrons to form the ammonium ion. All of the bonds in these ions are indistinguishable once formed, however.