Halite is composed of sodium (Na) and chloride (cl) with the Na+ and cl- ions alternating with one another in all three direction within astructure

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

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.

What is the percent by mass of magnesium sulfate in mgso4.7h2o