Mendeleev left several blank spaces in his original periodic table. what did those spaces represent? elements with unknown physical properties elements that did not fit into his pattern elements that had yet to be discovered elements with variable atomic masses

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.