6. Molecules in which the atoms are held together by __________ bonds have the strongest chemical linkages.

A. noncovalent
B. covalent
C. ionic
D. hydrogen

7. Salt dissolves well in water as water molecules

A. form hydrogen bonds with the positively and negatively charged ions
B. make nonpolar covalent bonds with the positively charged ions only
C. surround the ions because of their charge but do not form hydrogen bonds
D. share electrons with the ions to make polar covalent bonds

8. Buffer solutions

A. will always have a pH of 7
B. are rarely found in living systems
C. cause a decrease in pH when acids are added to them.
D. tend to maintain a relatively constant pH.

9. A Bronsted acid becomes __________ upon losing a proton.

A. highly reactive
B. its conjugate acid
C. its conjugate base
D. a hydronium ion

10. Most of the important functional groups in biological molecules contain

A. oxygen and/or nitrogen and are acidic
B. oxygen and a phosphate
C. nitrogen and a phosphate
D. oxygen and/or nitrogen and are polar