How do you convert the measured mass of a substance to moles?

Anurse practitioner prepares an injection of promethazine, an antihistamine used to treat allergic rhinitis. if the stock bottle is labeled 25 mg/ml and the order is a dose of 11.0 mg , how many milliliters will the nurse draw up in the syringe?

State the formula for density in words and mathematical symbols

Nuclear fusion is the source of energy for stars. besides hydrogen, which other element is most likely also common in stars?