In a three-reaction system, the first two reactions are endothermic with AH values of AH1=101 kJ and AH2 = 358 kJ, respectively. If the final reaction is exothermic, what is the minimum value of AH3 that would make the overall reaction exothermic? Show your work and explain your reasoning very carefully.

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Explanation:

The total reaction when it comes to a three-reaction system can be endothermic, that is when two of the reaction is exothermic although it is very rare since the 2 exothermic reactions will have to be of smaller size combined H° than that of the endothermic reaction. If that action is absent then the reaction cannot be endothermic.

Kindly check the attached image below to see the complete solution to the question above.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.