Neon is a "noble gas," and is chemically inert. Thus, without a lot of chemical trickery, there is no element that naturally reacts with neon.
Fluorine is the most reactive element.
Among neon, argon, and helium, neon is the most reactive because it tends to form compounds with other elements under extreme conditions. Helium and argon are noble gases and are generally unreactive due to their stable electronic configurations.
Fluorine(F2) is the most reactive element, known to react with even Xenon, Krypton, Gold, Platinum, etc.
The noble gases: Helium, neon, etc.
If by vital you mean most reactive, then the metal francium, Fr, is the most reactive element.
Hydrogen is the most chemically reactive among the elements listed. It readily reacts with other elements to form compounds, while helium, argon, and neon are inert gases and generally do not undergo chemical reactions under normal conditions.
Oh, dude, the most reactive element among those is fluorine. It's like the drama queen of the periodic table, always looking for someone to react with. Oxygen and nitrogen are just chilling, while neon is basically the cool kid who doesn't bother with anyone. So yeah, fluorine takes the crown for being the most reactive in that group.
Lithium in group 1 is more reactive than neon in group 18. Lithium readily reacts with water and air to form compounds, while neon is a noble gas and is very stable and unreactive due to its full valence shell.
Oxygen and chlorine would be the most chemically reactive, as they readily form compounds with other elements. Argon and neon are inert gases, meaning they are stable and do not readily react with other substances.
Fluorine
The most reactive is fluorine.
Potassium is most reactive with the element Oxygen. However, it should be noted that it is most reactive with a non-element: Water.