What is the ratio of the average rate of effusion of CH4 to that of NOF at 400 K

Darla claims that the first periodic table developed by mendeleev was not completely accurate, so it is not useful at all. harmony argues that it establish the periodic table we use today, making it more credible. who is correct and why? darla is correct, because a model that has any mistakes should be thrown out. darla is correct, because a good model would not need to change. harmony is correct, because mendeleev’s model had all of the information correct in the first version. harmony is correct, because mendeleev’s model made predictions that came true.

What is the molar mass of potassium nitrate, kno3

What is the main reason why some developing countries fear the increase the free trade policies around the world?