Im not entirely sure how to do this would someone mind answering it for me?

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

Calculate the number of moles of ethane in 100 grams

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.