Which of the following is not soluble in water?
a. potassium sulfide
b. iron (ii) bromide
c. iron (iii) hydroxide
d. iron (iii) nitrate
e. ammonium sulfate

explanation:

detials on each model with digrams

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72