Which element, under normal circumstances, does not combine chemically with other elements to form compounds? a) carbon b) lithium c) neon d) oxygen

            Option-C (Neon)

Explanation:
                     In order to understand this question, One should know about, "Why do Atoms React".
                     Everything in universe tends to have a stable state. In short the driving force behind every action and reaction is to gain stability.
                     Atoms also react to gain stability. The stability is in the completion of its valence shell.
                     Carbon, Lithium and Oxygen combines with other elements to complete their Octet. Like Oxygen gain two electrons, Lithium loose one electron etc. This gaining and loosing actions makes them reactive.
                     While in case of Neon, it belongs to Group VIII A element. These elements have their valence shell complete. A complete valence shell means a stable state. That is why Neon does not combine chemically.