Quantum numbers arise naturally from the mathematics used to describe the possible states of an electron in an atom. The four quantum numbers, the principal quantum number (n), the angular momentum quantum number (), the magnetic quantum number (m), and the spin quantum number (ms) have strict rules which govern the possible values. Identify all allowable combinations of quantum numbers for an electron.
Select all that apply.

a) n= 3 l= -2 ml=-1 ms= +1/2
b) n=3 l= 2 ml= -1 ms= -1/2
c) n= 4 l=4 ml=-1 ms= +1/2
d) n=2 l=1 ml=-1 ms=1
e) n=4 l=1 ml=2 ms=-1/2
f) n=5 l=4 ml=4 ms=+1/2

Salicylic acid is a very important acid. it is used to synthesize the aspirin by treating with acetic anhydride. a 0.2015-g sample of salicylic acid was dissolved in a 100.00-ml volumetric flask, and the solution was diluted to the mark. a 10-ml aliquot of this solution was titrated with standard naoh (0.01130 + 0.2% n) to a phenolphthalein faint pink color end point at 19.81 ml. (a) (calculate the normality of the salicylic acid solution used in the titration. (b) assuming the salicylic acid is pure, what is the equivalent weight of the salicylic acid? practice problems for the final exam (continued) (c) (calculate the inherent error in the determination of the equivalent weight you calculated in part (b). use the following absolute errors in the equipment /glassware when calculating the inherent error. 5.00-ml pipet: + 0.02 ml 100-ml volumetric flask: + 0.08 ml analytical balance: + 0.2 mg 25-ml buret: + 0.03 ml

Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium

Drag each pressure unit with the corresponding number to describe standard atmospheric pressure