Can someone help me please, I think it may be B but i'm not sure..

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

Which activity describes an application of topographic maps? check all that apply. recreation, such as camping and hiking engineering, such as the construction of roads and buildings science, such as mapping stars in the sky business, such as analyzing population centers science, such as analyzing surface features

What is the amount of energy for a photon that has a 125 cm wavelength