When work is done on an object, the object gains what?

Which object forms when a supergiant runs out of fuel? a red giant a black hole a white dwarf a neutron star

Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 45.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

How have the greenhouse gasses increased from the year 2000 to 2018