How many protons and neutrons are in an atom of B-13?

If 34.2 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 299 kelvin and 1.21 atmospheres? 2 li (s) + 2 h2o (l) yields 2 lioh (aq) + h2 (g)

Consider the elements bromine and chlorine; which elements has a larger ionic radius ?

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)