10. Which of the following statements concerning electrons is false? A) Electrons orbit the nucleus of an atom in defined orbitals. B) The outer shell of all atoms must contain eight electrons. C) An atom may have more than one valence shell. D) Electrons are negatively charged particles. E) All of the above are true; none is false. 11. Cola has a pH of 3; blood plasma has a pH of 7. The hydrogen ion concentration of cola is therefore A) 4 times greater B) 4 times smaller C) 400 times greater D) 10,000 times greater E) 30,000 times greater than the hydrogen ion concentration of blood plasma. 12. Which of the following statements about water is true? A) Water has a low heat of vaporization. B) Water has a high specific heat. C) When water freezes, it gains energy from the environment. D) All of the above E) None of the above 13. A macromolecule with many hydrogen and peptide bonds is most likely a A) carbohydrate. B) lipid. C) protein. D) nucleic acid. E) vitamin. 14. A five-carbon sugar is known as a A) glutamine. B) glucose. C) hexose. D) pentose. E) None of the above