no, because electron gain enthalpy increase left to right across the period in periodic table while atomic radius decrease left to right across the period

Introduction:
Electron gain enthalpy refers to the energy change that occurs when an atom or ion gains an electron to form a negatively charged ion. It is an important concept in understanding the reactivity and chemical behavior of elements. The atomic radius, on the other hand, is the distance between the nucleus and the outermost electron shell of an atom.

Relationship between Electron Gain Enthalpy and Atomic Radius:
The relationship between electron gain enthalpy and atomic radius can be explained by the following points:

1. Effective Nuclear Charge:
The effective nuclear charge experienced by an electron is determined by the balance between the attractive force of the protons in the nucleus and the repulsive forces of other electrons. As atomic radius increases, the distance between the nucleus and the outermost electron shell also increases. This results in a decrease in the effective nuclear charge experienced by the outermost electrons. Consequently, the attraction between the nucleus and the incoming electron weakens.

2. Shielding Effect:
Shielding effect refers to the repulsion between electrons in different energy levels or shells. As the number of occupied electron shells increases, the shielding effect also increases. This leads to a decrease in the effective nuclear charge experienced by the outermost electron. As a result, the attraction between the nucleus and the incoming electron decreases.

3. Electron Density and Electron Repulsion:
Electron density refers to the concentration of electrons in a given volume of space. When the atomic radius increases, the volume of space around the nucleus also increases. This allows for a larger electron cloud, resulting in a decrease in electron density. With lower electron density, there is less electron-electron repulsion, leading to a decrease in the energy released when an electron is added.

Conclusion:
In conclusion, electron gain enthalpy is inversely proportional to atomic radius. As the atomic radius increases, the effective nuclear charge, shielding effect, and electron density decrease. These factors collectively weaken the attraction between the nucleus and the incoming electron, resulting in a decrease in the energy released during electron gain enthalpy. However, it is important to note that while the trend generally holds true, there may be exceptions due to other factors such as subshell stability and electron-electron interactions.