Acetylene is used for gas welding and metal cutting.
Tips
usage
乙 ('second heavenly stem') is the chemistry prefix for C₂ compounds - 乙烷 ethane, 乙烯 ethylene, 乙炔 acetylene. The full series is 甲/乙/丙/丁 = C₁/C₂/C₃/C₄. 炔 specifically marks a triple bond (alkyne).
