Put the substance in a 25 mL beaker. Now, observe and record the following:
- state of matter:
appearance and texture:
crystalline structure:

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.

it's all four options.