A 0.45g sample of mineral ore is analysed for chromium and found to contain 0.560mg ccr2o3.Express the concentration of cr2o3 in the sample as:a percentage, part per thousand, part per million and part per billion?

Which of the following describes a situation where competition between producers exists

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.

How many moles of no2 will form when 3.3 moles of cu are reacted with excess hno3?