A system receives 575 ) of heat and delivers 425 ) of work. Calculate the change in the internal energy. AE, of the system.

Both 1,2−dihydronaphthalene and 1,4−dihydronaphthalene may be selectively hydrogenated to 1,2,3,4−tetrahydronaphthalene. one of these isomers has a heat of hydrogenation of 101 kj/mol (24.1 kcal/mol), and the heat of hydrogenation of the other is 113 kj/mol (27.1 kcal/mol). match the heat of hydrogenation with the appropriate dihydronaphthalene.

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.

If a particle has z = 25 and 23 electrons, what is its charge?