Hey guy's is anyone free to talk im soo bored, any cute boys there?

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.

This image is an example of a(n) a) atom. b) compound. c) mixture. d) molecule.

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?