Final answer:
The elements Ne, C, P, S, Li are ordered from least reactive to most reactive based on their chemical properties and position in the periodic table, with Neon being the least reactive and Lithium, an alkali metal, being the most reactive.
Step-by-step explanation:
To order the elements Li, S, P, C, Ne from least reactive to most reactive, we must consider their position on the periodic table and their chemical properties. Neon (Ne) is an inert or noble gas and is the least reactive because it has a complete outer shell of electrons, making it very stable and unlikely to react. Carbon (C) is relatively unreactive under normal conditions, but can form four bonds with other elements. Phosphorus (P) is more reactive than carbon as it can form three bonds and reacts with oxygen in the air at room temperature. Sulfur (S) is also quite reactive, commonly found in nature in its elemental form and known to react with many metals and nonmetals. Lithium (Li) belongs to the group of alkali metals, which are the most reactive group of metals in the periodic table. Therefore, the order from least reactive to most reactive is Ne, C, P, S, Li.