Which is the wrong order for the stated property ? .

Options

A. `Ba gt Sr gt Mg` : atomic radius
B. `F gt O gt N `: first ionisation enthalipy
C. `Cl gt F gt I` : electron affinity
D. `O gt Se gt Te` : electronegativitly

Answer

B

Explanation

On moving along the period, ionisation enthalpy increases.
In second period, the order of ionisation enthalpy should be as follows : `F gt O gt N`
But N has half-filled structure, therefore, it is more stable than O. That’s why its ionisation enthalpy is higher than O. Thus, the correct order of IE is
`F gt N gt O`.