Answer:
the correct choice would be: 4. Reaction rates are not related to spontaneity.
Explanation:
The speed of reaction is independent of spontaneity, since it depends on other factors such as the amount of reagent.
The amount of reagent is one of the variables that most influences the speed of reaction, the greater the amount of reagent, the faster the reaction will be and thus the speed will be increased.
The rate of reaction between oxygen and copper is higher at high temperature. The rate of reaction between oxygen and copper is lower at room temperature.
at high temperature copper penny will react with oxygen as shown below

The reaction does not occur easily at room temperature
We can say that the reaction between copper and oxygen is an endothermic reaction so the rate of reaction is high at high temperature.
The bond energy of oxygen molecules need energy to react with copper and form copper oxide.
Answer:
Explanation:\
Elastic energy is energy stored in an object when there is a temporary strain on it – like in a coiled spring or a stretched elastic band.
The energy is stored in the bonds between atoms. The bonds absorb energy as they are put under stress and release the energy as they relax (when the object returns to its original shape).
35g Mg x 1mol / 24g = 840 mol
6) C and 7) C
I hope this helps