How many energy levels does calcium have?

Earth's axis of rotation is tilted at an angle of 23.5 degrees. what is one change you would see on earth if its axis was not tilted?

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next

How many grams of phosphorus are contained in 5.09 moles of phosphorus?