Write a procedure to identify the salt and metal

Which statement about sound is not true? a. air particles travel with sound waves. b. sound waves cannot travel through a vacuum. c. sound waves exist even if no one hears them. d. air particles vibrate along the path of a sound wave.

Calculate the number of molecules present in 0.750 mol of mgo.

In an exothermic reaction at equilibrium, what is the effect of lowering the temperature? a. the reaction makes more products. b. the reaction makes more reactants. c. the reaction is unchanged.