How do you recognize ionic or molecular compounds from reading their chemical formulas

Which type of orbits are found in the principal energy level n = 2 a - s b - s, f c - s, d d - s, p e - s, p, d

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.

56.16 gregor mendel was the first scientist to use statistics to analyze scientific data. before mendel's experiments, scientists believed that organisms acquired traits from their environment and passed them on to their offspring. after mendel's discoveries were accepted, scientists realized that traits passed to offspring were the result of genes being passed from parents to offspring. this is an example of pls