In the first reaction a fluoride ion, F−, gives up an electron pair to boron trifluoride to form the product tetrafluoroborate.
ɪnðə fˈɜːst ɹɪˈækʃən ɐ flˈʊɹɹaɪd ˈaɪɑːn, ˈɛf mˈaɪnəs, ɡˈɪvz ˌʌp ɐn ᵻlˈɛktɹɑːn pˈɛɹ tə bˈoːɹɑːn tɹˈaɪflʊɹɹˌaɪd tə fˈɔːɹm ðə pɹˈɑːdʌkt tˈɛtɹɐflˌʊɹɹəbɚɹˌeɪt.