Analyzing lone pairs on central atoms:
HNO₃: N is central with 3 bonds and 0 lone pairs
H₂SO₄: S is central with 4 bonds and 0 lone pairs
NF₃: N is central with 3 bonds and 1 lone pair
O₃: Central O with 2 bonding regions and 1 lone pair
NF₃ has maximum lone pairs (1) with the clearest structure. N undergoes sp³ hybridization with 1 lone pair and 3 bonding pairs giving trigonal pyramidal geometry. The F-N-F bond angle is reduced from ideal tetrahedral 109.5° due to lone pair repulsion, resulting in approximately 102°.