What is the purpose of a physical model?

Which form of relativism states that people rely on their own standards of right and wrong when making a decision?

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.

8. how much enthalpy/heat is transferred when 0.5113gof ammonia (nh3) reacts with excess oxygen according| to the following equation: 4nh3 +502 - 4n0+ 6h20ah = -905.4j