Determine the value of the number ABCD
Determine the value of the number ABCDCorrect answers: 113
The first user who solved this task is Djordje Timotijevic.
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Thomas Midgley Jr.Born 18 May 1889; died 2 Nov 1944 at age 55.American engineer and chemist who discovered the effectiveness of tetraethyl lead (C2H5)4Pb in 1921 as an antiknock additive for gasoline. Knocking jars the wall of the automobile cylinders by the explosion instead of steadily pushing the cylinder back. This wastes a large percentage of the energy and damages the engine. He also developed carbon tetrafluoride (CF4) a cleaning agent and in 1930 dichlorofluoromethane (CCl2F2) later called "Freon". This is a non-toxic and non-flammable gas, unreactive at normal temperatures but able to be easily liquified by pressure alone. It replaced toxic gases previously used in home refrigeration. |