In BF3
All the B - F Bond are single covalents in nature
Boron-fluorine bond has some double bond character and this bond is delocalised
Bond energy and bond length of B - F bond indicate its single bond character
All the bond are ionic
Bond has double bond characteristics due to pΠ - pΠ back - bonding.
The correct increasing bond angle among BF3, PF3 and ClF3 follows the order