Using a more physics oriented approach, rather than a chemistry one, and looking to an energy point of view if possible. For example, why when ice turns into water there is a need for energy (heat)? I know in some extent that the energy is used into re-organizing the chemical bonds, but that seems very superficial. And also I don't really understand the more general cases, like things burning and "making fire". Thank you for the responses in advance, anything will be helpfull.