XF₃ is a Lewis acid, indicating the central atom X lacks a complete octet and can accept electron pairs. This is characteristic of Boron (B).
Boron in BF₃:
Valence electrons: 3
Steric number: 3 (three B-F bonds, no lone pairs)
Geometry: Trigonal planar
Hybridization: sp²
YF₃ is a Lewis base, indicating the central atom Y has lone pair(s) available to donate. This is characteristic of Nitrogen (N).
Nitrogen in NF₃:
Valence electrons: 5
Steric number: 4 (three N-F bonds + one lone pair)
Geometry: Trigonal pyramidal
Hybridization: sp³
Therefore, the hybridizations are sp² for XF₃ (Boron) and sp³ for YF₃ (Nitrogen).