Question

when the deviations from a periodic arrangment localised to the visibility of only several atom it is known as​

Answer 1

Answer:

The noble gases (historically also the inert gases; sometimes referred to as aerogens[1]) make up a class of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). Oganesson (Og) is variously predicted to be a noble gas as well or to break the trend due to relativistic effects; its chemistry has not yet been investigated.