Question

2) The atomic number of an atom is

A: the number of protons in the atom.

B: the number of neutrons in the atom.

C: the number of protons plus the number of electrons in the atom.

D: the number of protons plus the number of neutrons in the atom.

E:None of these choices are correct.

3) An example of one of the ways a pH buffer helps to maintain homeostasis is to

A: reduce the OH- concentration if pH decreases.

B: reduce the H+ concentration if pH decreases.

C: reduce the H+ concentration if pH increases.

D: increase the OH- concentration if pH increases.

E: increase the H+ concentration if pH decreases.

4) The smallest functional unit and associated structures of a living organism are

A: molecules and their atoms, bonds, and electrons.

B: proteins and amino acids.

C: water made of hydrogen and oxygen.

D: cells with nucleus, mitochondria, and ER.

E: atoms and their protons, neutrons, and electrons.

5) A significant role played by pH buffers is to

A: prevent fluctuations in the acidity of solutions.

B: increase the strength of acids and bases.

C: prevent fluctuations in the salinity of solutions.

D: limit major shifts in the amount of H+ and OH- in solution.

E: keep pH low.

6) The addition of a strong acid like HCl to an aqueous solution would result in

A: the release of H+ into the solution.

B: an increase in pH.

C: a decrease in pH.

D: both the release of H+ and an increase in pH.

E: both the release of H+ and a decrease in pH.

7) Five unknown compounds are added to water. Four of the compounds go into solution while one does not. What property does water possess that allows these four compounds to dissolve? Why might the fifth compound not dissolve?

A: The positive and negative charge in water will dissolve many substances; the substance is not structurally similar to water.

B: The nonpolar quality of water dissolves many substances; the substance is not structurally similar to water.

C: The positive charge of water dissolves many substances; the substance is too structurally similar to water.

D: The negative charge of water dissolves many substances; the substance is too structurally similar to water.

8) What type of bonds form from the unequal sharing of electrons?

A: ionic

B: electrostatic

C: polar covalent

D: hydrogen

E: nonpolar covalent

Answer 1

2)- ans.-A: the number of protons in the atom is called  atomic number of an atom

3)-Ans-B: reduce the H+ concentration if pH decreases.

4)-Ans-E: atoms and their protons, neutrons, and electrons.

5)-Ans.-D: limit major shifts in the amount of H+ and OH- in solution.

6)-Ans.-E: both the release of H+ and a decrease in pH.

7)-Ans.-A: The positive and negative charge in water will dissolve many substances; the substance is not structurally similar to water.

8)-Ans-C: polar covalent is  bonds form from the unequal sharing of electrons