A brief description of how three elements acquired their symbols.
The periodic symbol for lead is Pb. This is derived from the Latin word plumbum, meaning “soft metal”. Lead would have been known as plumbum nigrum, literally “soft black metal”. The Romans normally used lead for pipes (hence “plumber” and “plumbing”).
Gold has the symbol Au. This is also based on Latin: in the first and second centuries (C.E.), the Roman miners dislodged gold deposits from surrounding rock by blasting it with high-pressure jets of water. The Latin name for Gold was aurum.
The symbol of potassium is K. There is no Latin term for potassium (as it was not differentiated from sodium until 1702), but the K symbol is based on the Neo-Latin word kalium, thought to mean “alkali”.