Of the five elements Al, Cl, I, Na, Rb, which has the most exothermic reaction? (E represents an atom.) What name is given to the energy for the reaction? Hint: note the process depicted doesnotcorrespond to electron affinity

\({{\bf{E}}^ + }(g){\rm{ }} + {\rm{ }}{{\bf{e}}^ - } \to {\bf{E}}(g)\)

Considering the given elements \(A{l^ + },{\rm{ }}C{l^ + },{\rm{ }}{I^ + },{\rm{ }}N{a^ + },{\rm{ }}R{b^ + }\) with \(1 + \) charge. In an exothermic reaction, excess energy is given out. Observing the elements,

\(A{l^ + }\)will have filled s-subshell.

\(N{a^ + }\)will have filled p-subshell.

\(R{b^ + }\)will have filled p-subshell.

In the case of Cl, the electron will fall into the lowest 3p orbital. In the case of iodine, the electron will fall into a 5p orbital.

Observing the data mentioned above, we can conclude that Cl-atom will have the most exothermic reaction.

When an electron moves from a higher energy state to a lower energy state energy is released. This energy is released in form of heat is called exothermic energy.