Pls help its not hard ty

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

Compare and contrast physical changes with chemical changes.

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.