The order of energy of orbitals is `s lt p lt d lt f `

Explain the order of electronegativity: I lt Br lt Cl lt F .

STATEMENT-1: For hydrogen orbital energy increases as 1s lt 2s lt 2p lt 3s lt 3p lt 3d lt 4s lt 4p... STATEMENT-2: The orbital with lower (n+l) value has lesser energy and hence filled up first.

Arrange the following compounds in the increasing order of their densities. I lt II lt III lt IV , I lt III lt IV lt II , IV lt III lt II lt I , II lt IV lt III lt I

A student arranged the halide ions in the increasing order of polarisabillity as: F lt I lt Cl lt Br. Is this the correct order? If not write it in correct order