Reasons:

* Electron Configuration: Lithium has a single valence electron in its outermost shell, while Neon has a full octet (8 electrons) in its outermost shell. This means Lithium readily loses its valence electron to achieve a stable configuration, while Neon is very stable and reluctant to gain or lose electrons.

* Ionization Energy: Lithium has a relatively low ionization energy, meaning it requires less energy to remove its valence electron. Neon, on the other hand, has a very high ionization energy, making it extremely difficult to remove an electron.

* Electronegativity: Lithium has a low electronegativity, meaning it has a tendency to lose electrons. Neon has a very high electronegativity, making it unlikely to gain electrons.

Reactivity:

* Lithium is a highly reactive alkali metal that readily reacts with water, air, and acids.

* Neon is a noble gas that is extremely unreactive and does not form chemical bonds under normal conditions.

Conclusion:

Due to its electron configuration, ionization energy, and electronegativity, Lithium is significantly more reactive than Neon. Neon's stable electron configuration makes it practically inert.