tìm công thức hoá học của R và O biết trong hợp chất oxi chiếm 50% về khối lượng. tính khối lượng bằng gam của 500 phân tử này.

What does the mass of 0.7891 mol of ferric oxide (fe2o3)

Which of the following natural processes is most likely to support the formation of an underwater sinkhole? a pollution buildup from deposited minerals b limestone cave collapsing due to changes in sea level c erosion of large amounts of sand moved by ocean waves d oxidation of rock formed by chemical weathering

How can carbon move from "land" to bodies of water? describe the way human impact has lead to increased levels of co2 in the atmosphere.