CBSE Class 10 Answered

The noble gases—helium, neon, argon, krypton, xenon, and radon—have the striking chemical property of forming few chemical compounds. This property would depend upon their possessing especially stable electronic structures (that is, structures so firmly knit that they would not yield to accommodate ordinary chemical bonds). During the development of modern atomic physics

The atoms of the alkaline-earth elements all have similar electronic structures, consisting of a pair of electrons (designated s electrons) in an outermost orbital, within which is a stable electronic configuration corresponding to that of a noble gas. The noble gas elements—helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn)—have generally complete

The theory of chemical bonding predicts two fundamentally different electron configurations for carbenes, either one of which may correspond to the ground state of the molecules (state of lower energy content) depending only on the nature of the atoms and groups attached to the divalent carbon atom. This duality arises from the fact that the two bonds of the carbene utilize only two of the four

this structure, they form a diffuse cloud of negative charge that occupies nearly the entire volume of the atom. The detailed structural arrangement of electrons within an atom is referred to as the electronic configuration of the atom. The electronic configuration determines not only the size of an individual atom but also the chemical nature of the atom. The classification of elements within