1. They established their monatomic and unreactive nature.

2. Elemental nitrogen is a very unreactive and inert material.

3. So the discovery of the unreactive monatomic gas argon by Lord Rayleigh and William Ramsay in 1895 came as a total surprise.

4. Argon is unreactive, so that it does not react with the metal filament even when hot.

5. As the nearly unreactive diatomic molecule N2, it is useful as an inert atmosphere or to dilute other gases.

6. In fact, most alkanes are unreactive except in extreme conditions, such as combustion or strong sunlight.

7. In such conditions the ice crystals of the cloud provide a suitable surface for conversion of unreactive chlorine compounds into reactive chlorine compounds which can deplete ozone easily.

8. The first concerns noble gases. Were it not for escape, chemically unreactive gases such as neon or argon would remain in an atmosphere indefinitely.

9. With reference to above test results, which gas os the most unreactive?