Ninety-nine percent of all the matter that can be abserved in universe exists as?

Achemist has dissolved a certain substance in water. the chemist knows that more of the substance could be dissolved into the water before it stops dissolving. therefore

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

What is the atomic number of an atom that has 6 protons