Write a possible full set of quantum numbers for the electron gained when a bromine atom (br) becomes a bromide ion (br^−).

The answer is n = 4 , l = 1, m= +1 , ms = -1/2

Explanation:

When br atom gains one electron its atomic number becomes

36 br = 35

electronic config. = [ar] 3d 104s 24p5 br- = 36 = [ar] 3d 104s 24p6

so the electron goes into 4p that means

n = 4 , l = 1, m= +1 , ms = -1/2

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"