Erik has a handful of whitish-gray stones with a nonmetallic luster that leave a gray streak. They have a hardness of 6 What does he have?

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 other elements contain the same number of outer electrons as sodium

What effect might melting sea ice have for people who live in coastal areas?