What are the casues of global warming?

Initially, the balloon had 3.0 liters of gas at a pressure of 400 kpa and was at a temperature of 294 k. if the balloon is cooled to 277 k and its volume decreased to 1 l, what will the new pressure in the balloon be?

Given the following equation: 2a1 + 3mgcl2 --> 2alcl3 + 3mg how many moles of aluminum chloride are produced from 2.5 moles of magnesium chloride?

Athe top of a hill, an athlete on a skateboard has x joules of mechanical energy. how much mechanical energy will she have at the bottom of the hill? ignore the effects of friction.