Endothermic and exothermic would appreciate the help

Explanation:

In general, formation of bonds is always exothermic and bond breaking is always endothermic. In the methane-oxygen combustion reaction bonds in the reactants methane and oxygen are broken (endothermic) and bonds in carbon dioxide and water are formed (exothermic). One rule to keep in mind about all reactions whether overall energy change is endothermic or exothermic is that for the product compounds to form they must move to a lower energy level than the reactants. This will always translate into stronger bonds in the product compounds than the reactant compounds, otherwise the reaction would not occur.

Now, please understand that the energy lost on formation of each product compound (exothermic) is not the same as the 'overall' energy change of a reactions. Products form from elements with atomic structures ready to bond. The following diagram may be of interest in that it shows breaking of reactant bonds to push the elements into atomic states followed by bond formations to give product compounds.

CH₄ + 2O₂ => CO₂ + 2H₂O

 ↓ (endo)            ↑(exo)

     ··C·· + 4H· + 4·:O:·   <= (elements in atomic form ready to bond)

The above diagram refers to element to element interactions. The overall energy change of the reaction may be endothermic or exothermic. The combustion reactions are overall exothermic but the interaction of elements is endothermic for breaking reactant bonds and exothermic for formation of product bonds.

=> Sure hope this helps, but let me know if you need more explanations.

a chemical reaction happens

explanation: