only NF3 and PF3 is polar because they have lone pairs. BF3 and CF4 are non- polar because they don\'t have lone pairs. MgF2 is ionic, and polarity only applies to covalent bonding. Solution only NF3 and PF3 is polar because they have lone pairs. BF3 and CF4 are non- polar because they don\'t have lone pairs. MgF2 is ionic, and polarity only applies to covalent bonding..