Lewis acids and bases studied chemical bonding. In 1923, Lewis wrote "An acid substance is one which can employ an electron lone pair from another molecule in completing the stable group of one of its own atoms." The Brønsted–Lowry acid–base theory was published in the same year. The two theories are distinct but complementary. A Lewis base is also a Brønsted–Lowry base, but a Lewis acid doesn't need to be a Brønsted–Lowry acid. The classification into hard and soft acids and bases (HSAB theory) followed in 1963. The strength of Lewis acid-base interactions, as measured by the standard enthalpy of formation of an adduct
Orlando Magic his option for the 2010–11 season. They did the same for general manager Otis Smith, which would keep him in that position through the 2011–12 season. The Magic were without Rashard Lewis for the first 10 games of the 2009–10 season. Lewis tested positive for an elevated testosterone level that was caused by an over-the-counter supplement containing a substance banned by the league. To make matters worse, Vince Carter suffered a left ankle injury in just the second game of the season. Carter's injury turned out to be not too serious, but caused him to miss the next five games.