If this were a frictionless plane, what would be the ideal mechanical advantage?

a h + 9h = 10h
b h ÷ 9h = 1 ÷ 9
c 9h ÷ h = 9

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.

Which statement describes the phase change that occurs when dry ice is placed in an open container at room temperature?

Answer asap need it by wednesday morning calculate the ph of 0.02m hcl best answer will be brainliest