Some nighttime partygoers wear glow-inthe-dark necklaces. the necklaces start glowing once they are ""activated"" by snapping the necklace in a way that allows two chemicals to react and emit light in the form of chemiluminescence. is the chemical reaction exergonic or endergonic? explain your answer.

Exergonic

Explanation:

The process is exergonic because it transfer energy from the system to the surrounds in the shape of light. It happens because of the Gibbs free energy (ΔG) which is lower than zero. If the reaction was Endergonic, the Gibbs free energy should be higher than zero. We can calculate it from the GIbbs-Helmholtz equation: ΔG = ΔH - T . ΔS. ΔH is enthalpy, T is the temperature and ΔS is entropy.

away from the curb

explanation:

the wheels would then hit the curb if it started to rolling, decreasing the chance of an accident.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !