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
Ibis GS-730 Super Magic a gross weight of , giving a useful load of . With maximum full fuel of the payload for pilot, passenger and baggage is . The standard day, sea level, no wind, take off is and the landing roll is . Ibis GS-730 Super Magic The Ibis GS-730 Super Magic is a Colombian STOL homebuilt aircraft that was designed and produced by Ibis Aircraft of Cali, introduced in 2007. When it was available the aircraft was supplied as a complete ready-to-fly-aircraft or as a kit for amateur construction. Production has been completed and as of 2011 the aircraft was no