List three changes of state during which energy is absorbed

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure

Two metal blocks that have slightly different temperatures are placed next to one another. after five minutes, they both have lower but equal temperatures. according to the law of conservation of energy, what  most likelyhappened? energy was created inside the blocks.energy was destroyed inside the blocks.energy was absorbed into the blocks from outside the system.energy was transferred from the warmer block to the cooler block.

How do dying stars contribute to the formation of planets