sentence2_structure: Carbon (c)<>is<>essential to living organisms<>because carbon bonds in many ways with itself to form chains$$$carbon bonds in many ways with itself<>to form<>chains
sentence1: The Hiyama-coupling is a palladium-catalyzed cross-coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon-carbon bonds (C-C bonds).
sentence2: Carbon (c) is essential to living organisms because carbon bonds in many ways with itself to form chains.
question: What characteristic of carbon (C) makes it essential to living organisms?