Please, observe that it is not right to say that a substance content heat.
Heat is not something that a body or substance content. Heat is the transmission of energy due to difference of temperatures.
An endothermic reactions is that where the reactants abosorb energy from the surroundings to occur. The products, then, will be higher in energy than the reactants while the surroundings get colder.
Answer:
The physical properties of a solution are different from those of the pure solvent. ... Colligative properties are those physical properties of solutions of nonvolatile solutes that depend only on the number of particles present in a given amount of solution, not on the nature of those particles.
Answer: The Kinetic Molecular Theory of Matter
Explanation: The answer is: B. Collisions between gas particles are elastic; there is no net gain or loss of kinetic energy.
The Kinetic Molecular Theory of Matter