What is not a molecule

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

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.