A balloon expands from 0.210 L to 3.95 L. The atmospheric pressure is 0.970 atm. How much work was done on the surroundings?

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?

How many protons, electrons, and neutrons are in each of the following isotopes? a. zirconium-90 b. palladium-108 c. bromine-81 d. antimony-123

Calculate the energy required to ionize a hydrogen atom to an excited state where the electron is initially in the n = 5 energy level. report your answer in kilojoules