The bulb of a thermometer is placed in your mouth. Which of the following explains why the level of the liquid rises in the thermometer? A. Hot air rises inside the thermometer.
B. Heat energy changes into light energy.
C. The liquid expands when heated.
D. Heat can change a solid into a liquid.

i think it's c. i'm not sure but i think so.

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.