Ascientist in london and a scientist in california both conducted independent investigations that produced similar results. what does this mean about the data that was collected?

Which compound most likely has the greatest bond energy?

Dumbledore decides to gives a surprise demonstration. he starts with a hydrate of na2co3 which has a mass of 4.31 g before heating. after he heats it he finds the mass of the anhydrous compound is found to be 3.22 g. he asks everyone in class to determine the integer x in the hydrate: na2co3·xh2o; you should do this also. round your answer to the nearest integ

2.38g of black copper (ii) oxide is completely reduced by hydrogen to give copper and water. what are the masses of copper and water formed? ?