The reaction "Li + e -> Li(1-)" is energetically easier than the reaction "Li -> Li(1+) + e."
To understand why, we need to consider the concept of ionization energy. Ionization energy is the energy required to remove an electron from an atom or ion. In the case of lithium (Li), it takes less energy to add an electron to form Li(1-) than to remove an electron to form Li(1+).
When Li gains an electron (Li + e -> Li(1-)), it undergoes electron capture, a process that involves the addition of an electron to the atom. This process releases energy since the electron is attracted to the positively charged nucleus of the lithium atom, resulting in a more stable Li(1-) ion.
On the other hand, when Li loses an electron (Li -> Li(1+) + e), it undergoes ionization, which requires energy input. Removing an electron from an atom means overcoming the electrostatic attraction between the negatively charged electron and the positively charged nucleus. This process is energetically unfavorable and requires a higher amount of energy compared to electron capture.
Therefore, due to the lower energy requirement for electron capture, the reaction "Li + e -> Li(1-)" is easier according to energetics compared to the reaction "Li -> Li(1+) + e."