Atoms with the same atomic number but different atomic mass are called
a. prototypes.
b. subtypes.
c. isotopes.
d. ions.

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments

What is the mass of naoh that would have to be added to 500 ml of a solution of 0.20 m acetic acid in order to achieve a ph of 5.0?

Calculate the ph of a .10m nh4cl solution. the kb value for nh3 is 1.8×10^-5