Question

In general, the property (magnitudes only) that shows an opposite trend in comparison to other properties across a period is:

• A. Atomic radius
• B. Electronegativity
• C. Electron gain enthalpy
• D. Ionization enthalpy

Answer 1

The correct option is A Atomic radius

On moving from Left to Right along a period:
Atomic Radius $\to$ Decreases
Electronegativity $\to$ Increases
Electron Gain Enthalpy $\to$ Increases
Ionisation Enthalpy $\to$ Increases

Hence, atomic radius shows the opposite trend in comparison to other properties.