NEET Practice Questions (MCQs) with Answers & Solutions

Noble gases are monoatomic, meaning they exist as single atoms rather than molecules. Vibrational energy is associated with the vibrations of atoms within a molecule, so monoatomic gases do not possess vibrational energy. This is why noble gases, being monoatomic, do not have vibrational energy.

Argon was discovered by Sir William Ramsay and Lord Rayleigh. Ramsay is credited with the discovery of argon in 1894. He isolated the gas and identified it as a new element, which was later confirmed by Rayleigh.

Argon, being a noble gas, has a complete set of electrons in its outer shell, making it chemically inert. This means it does not readily react with other elements or compounds, showcasing the least chemical activity compared to the other options.

Noble gases do not react with other elements because they have a completely filled valence shell, making them chemically inert. This stable electron configuration makes them very stable and unreactive.

Helium is added to oxygen supply used by deep sea divers because it is less soluble in blood than nitrogen at high pressure. This helps to prevent nitrogen narcosis and decompression sickness.

Krypton (Kr) is not typically obtained during radioactive disintegration. Noble gases like Helium (He) are used to produce low temperatures, Argon (Ar) is used in electric bulbs, and Radon (Rn) has a half-life of 3.8 days. Therefore, option o2 is incorrect.

The noble gas configuration is characterized by a completely filled valence shell. For example, Neon (Ne) has the electronic configuration $1s^2 2s^2 2p^6$ and Argon (Ar) has $1s^2 2s^2 2p^6 3s^2 3p^6$. Thus, option o2 which represents $1s^2 2s^2 2p^6 3s^2 3p^6$ is a noble gas configuration.

Krypton (Kr) is a noble gas that has a complete valence shell, giving it zero valency. Noble gases are known for their lack of reactivity due to their stable electronic configuration, which means they typically do not form bonds and have zero valency. Hence, option o4 is correct.