3. 78 mL of 2.5 M phosphoric acid is neutralized with 500 mL of potassium hydroxide. What is the concentration of the base?

Hence, concentration of base is 1.17 M

They are all full and don't need any more electrons in there outer shell.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.