Is a new substance form a physical or chemical change?

Substance x has a fixed volume, and the attraction between its particles is strong .substance y had widely spread out particles and can be compressed what can most likely be concluded about these substances

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.

In an exothermic reaction the bonding energy of the product is: less than the reactants same as the reactants greater than the reactants dependent upon the presence of a catalyst