What is the average atomic mass of Potassium if if 93.12% exists as potassium-39 (38.964 amu) and the rest exists as potassium-41 (40.961 amu)?

According to the diagram; a) identify the anode of the cell and write the half-reaction that occurs there b) write the overall equation for the reaction that occurs as the cell operates c) calculate the value of the standard cell potential ,e cell. d)write the shorthand notation of the cell above e)indicate the flow of the electrons on the diagram

You are making a solution of calcium chloride dissolved in water. you add solid, stir, and it dissolves. you add just a spatula tip full, stir, and the solid does not dissolve. how could you describe the solutions before and after adding the spatula tip amount

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?