Complex sentence: Silver is produced during certain types of supernova explosions by nucleosynthesis from lighter elements through the r-process, a form of nuclear fusion that produces many elements heavier than iron, of which silver is one.
Split into simpler sentences: Silver is produced from lighter elements through the r-process, a form of nuclear fusion believed to take place during certain types of supernova explosions. This produces many elements heavier than iron, of which silver is one.