I need help ASAP! Calculate the pH of the resulting solution for the neutralization of 100 mL of 0.050 M NH3 with 0.1 M HCL. (Kb for NH3 is 1.8 x 10^-5).

a) after adding 40.00 mL of HCl
b) after adding 70.00 mL of HCl
c) after adding 100.00 mL of HCL

All work is needed for full credit

Flourine is found to undergo 10% radioactivity decay in 366 minutes determine its halflife

Which of these conditions most likely produces an unstable isotope?

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.