PHYL141 CH 2 Review Questions

11. When an atom donates an electron to another atom, it becomes... A) an ion B) an anion C) non-polar D) all of the above

A) an ion

6. The characteristic that gives an element its distinctive properties is its number of ________. A) protons B) neutrons C) electrons D) atoms

A) protons

24. Ty is three years old and as a result of a "stomach bug" has been vomiting for about 24 hours. His blood pH is 7.48. What does this mean? A) Ty's blood is slightly acidic. B) Ty's blood is slightly alkaline. C) Ty's blood is highly acidic. D) Ty's blood is within the normal range

B) Ty's blood is slightly alkaline.

5. The smallest unit of an element that still retains the distinctive behavior of that element is an ________. A) electron B) atom C) elemental particle D) isotope

B) atom

28. A pentose sugar is a part of the monomer used to build which type of macromolecule? A) polysaccharides B) nucleic acids C) phosphorylated glucose D) glycogen

B) nucleic acids

20. CH4 is methane. This compound is ________. A) inorganic B) organic C) reactive D) a crystal

B) organic

12. A substance formed of crystals of equal numbers of cations and anions held together by ionic bonds is called a(n) ________. A) noble gas B) salt C) electrolyte D) dipole

B) salt

32. The ability of an enzyme's active sites to bind only substrates of compatible shape and charge is known as ________. A) selectivity B) specificity C) subjectivity D) specialty

B) specificity

30. In DNA, nucleotide bonding forms a compound with a characteristic shape known as a(n) ________. A) beta chain B) pleated sheet C) alpha helix D) double helix

D) double helix

41. The pH of lemon juice is 2, and the pH of orange juice is 4. Which of these is more acidic, and by how much? What does this mean?

Lemon juice is one hundred times more acidic than orange juice. This means that lemon juice has a one hundred-fold greater concentration of hydrogen ions.

37. In a hurry one day, you merely rinse your lunch dishes with water. As you are drying your salad bowl, you notice that it still has an oily film. Why was the water alone not effective in cleaning the bowl?

Water is a polar molecule. It has a region of weakly positive charge and a region of weakly negative charge. These regions are attracted to ions as well as to other polar molecules. Oils are nonpolar, andarerepelledbywater.

4. Together, just four elements make up more than 95 percent of the body's mass. These include ________. A) calcium, magnesium, iron, and carbon B) oxygen, calcium, iron, and nitrogen C) sodium, chlorine, carbon, and hydrogen D) oxygen, carbon, hydrogen, and nitrogen

D) oxygen, carbon, hydrogen, and nitrogen

39. AB +CD → AD + BE Is this a legitimate example of an exchange reaction? Why or why not?

It is not. An exchange reaction might be AB+CD→AC+BD or AB+CD→AD+BC. In all chemical reactions, including exchange reactions, the components of the reactants are identical to the components of the products. A component present among the reactants cannot disappear, nor can a component not present in the reactants suddenly appearintheproducts.