What is a main reason why the scientific model of atoms is considered a theory rather than a law?

Over time it has been changes

Explanation:

A law is something that is in nature and predicts what the result will be without having to explain

A theory is always changing when new information is provided and supports what is being tested.

So this is why it is describes as a theory instead of a law.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.