Free radicals, molecules with unpaired electrons, play a large role in most reactions of alkanes, such as cracking and reformation where long-chain alkanes are converted into shorter-chain alkanes and straight-chain alkanes into branched-chain isomers.
fɹˈiː ɹˈædɪkəlz, mˈɑːlɪkjˌuːlz wɪð ʌnpˈɛɹd ᵻlˈɛktɹɑːnz, plˈeɪ ɐ lˈɑːɹdʒ ɹˈoʊl ɪn mˈoʊst ɹɪˈækʃənz ʌv ˈælkeɪnz, sˈʌtʃ ɐz kɹˈækɪŋ ænd ɹᵻfoːɹmˈeɪʃən wˌɛɹ lˈɔŋtʃˈeɪn ˈælkeɪnz ɑːɹ kənvˈɜːɾᵻd ˌɪntʊ ʃˈɔːɹɾɚtʃˈeɪn ˈælkeɪnz ænd stɹˈeɪttʃˈeɪn ˈælkeɪnz ˌɪntʊ bɹˈæntʃttʃˈeɪn ˈaɪsəmɚz.