Electron affinity is the energy released when an electron is added to a neutral atom in the gaseous state. In this response, we will discuss why the electron affinity of argon is less than neon.


The atomic structure of argon and neon plays a significant role in determining their electron affinities. Both elements belong to the noble gas group and have a complete valence shell consisting of eight electrons. However, argon has a larger atomic number and a greater number of electrons in its inner shells than neon.


The effective nuclear charge is the net positive charge experienced by an electron in an atom. It is affected by the number of protons in the nucleus and the number of electrons in the inner shells. The greater the effective nuclear charge, the more strongly the nucleus attracts electrons, and the higher the electron affinity.


The shielding effect is the reduction in the effective nuclear charge experienced by an electron due to the presence of other electrons in the atom. The greater the number of inner electrons, the greater the shielding effect, and the lower the effective nuclear charge. This means that the outermost electrons are not held as strongly by the nucleus, and the electron affinity is lower.


In conclusion, the electron affinity of argon is less than neon because of its larger atomic number and greater number of electrons in its inner shells. This results in a greater shielding effect, and thus a lower effective nuclear charge, which leads to a lower electron affinity.

Because nuclear affinity of argon is greater than neon .greater the nuclearcharge greater electron affinity