A 0.500 gram sample of nitrogen combines with 1.140 g of oxygen to form NO2. If the atomic mass of oxygen is 16.000, calculate atomic mass of nitrogen to form this data.

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?

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.