How does E. Mulsion, celebrity food scientist, define a physical reaction and what examples does he give?

Incomplete question. However, I assumed you are referring to the comments made in the online animated video (Chemical and Physical changes)  by celebrity food scientist E. Mulson.

Explanation:

Recall in the video animation that E. Mulson defines physical reaction as occurring when "molecules in a substance stay the same, both before and after".

An example he gave was that of an orange getting juiced, the molecules remain the same before juicing, and after.

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.

c8h10 is your answerr