In a double-replacement reaction: one of the products is always a gas. one of the products must be an element. positive ions are exchanged between two compounds. all of the above

According to each substances heat of fusion, which of the items below requires more heat to be added per gram of substance to go from solid to liquid? silver sulfur water lead

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.

Use the periodic table to complete this equation that represents nuclear fission processesun - ba c 3 n