What do silk and tears belong to in chemistry in the poem "Spring silkworms die when silkworms die, and wax torches turn to ashes before tears dry up."

1. Silk is mainly protein.

2. Candles are usually made of paraffin. The composition of wax oil is still paraffin. Paraffin wax is obtained from the waxy fraction of petroleum through cold pressing or solvent dewaxing. Paraffin is a mixture of several higher alkanes, mainly n-docosane (C22H46) and n-octadecane (C28H58), containing about 85% carbon elements and about 14% hydrogen elements.