Which describes the enthalpy change associated with an endothermic reaction?

it is negative because the enthalpy of the products is greater than the enthalpy of the reactants.

it is positive because the enthalpy of the products is greater than the enthalpy of the reactants.

it is negative because the enthalpy of the reactants is greater than the enthalpy of the products.

it is positive because the enthalpy of the reactants is greater than the enthalpy of the products.

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.

The activation energy for the reaction no2(g)+co2(g)⟶no(g)+co(g) is ea = 300 kj/mol and the change in enthalpy for the reaction is δh = -100 kj/mol . what is the activation energy for the reverse reaction?