Every element in group one has electron in its outer shell. Every element in group two has electrons in its outer shell. need help

What is the value of keq for the reaction expressed in scientific notation

Which organism develops breathing organism develops breathing organs from pharyngeal arches? shark, spider, sea star, sea horse

The amount of iron in ore can be quantitatively determined by titrating a solution of the unknown with a standard solution of dichromate, cr2o72−. the net ionic equation is 6fe2+(aq)+cr2o72−(aq)+14h+(aq)→6fe3+(aq)+2cr3+(aq)+7h2o(aq) part a the titration of 25.0 ml of an iron(ii) solution required 18.0 ml of a 0.230 m solution of dichromate to reach the equivalence point. what is the molarity of the iron(ii) solution?