What is being reduced?

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

Which atom or ion is the largest? 0 a. 0 0 0 0 e. li

Which buffer would be better able to hold a steady ph on the addition of strong acid, buffer 1 or buffer 2? explain. buffer 1: a solution containing 0.10 m nh4cl and 1 m nh3. buffer 2: a solution containing 1 m nh4cl and 0.10 m nh3