What is the mass of a drop of water containing 4.55 x 10^ 22 H2O molecules

You are performing an experiment in a lab to attempt a new method of producing pure elements from compounds. the only problem is that you do not know what element will form. by your previous calculations you know that you will have 6.3 moles of product. when it is complete, you weigh it and determine you have 604.4 grams. what element have you produced?

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

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?