The Chemical Context of Life

1. Chapter 2 The Chemical Context of Life Questions prepared by William Wischusen Louisiana State University Jung Choi Georgia Institute of Technology

2. A patient is diagnosed with anemia resulting from iron deficiency. What is the best way to supplement the patient’s diet with iron? The patient should add fine metallic iron filings to his morning cereal. The patient should periodically suck on rusty nails. The patient should cook with a cast-iron skillet and eat vegetables with high iron content, such as spinach. The patient should eat more red meat.

3. Based on the periodic table shown here, which elements will most likely form an ionic bond? Na and Cl, and Li and F C and O N and O Si and Cl all of the above

4. Based on the periodic table shown here, which elements will most likely form a polar covalent bond? Na and Cl C and O, and N and O Si and Cl, and H and H all of the above none of the above

5. Based on the periodic table shown here, which elements will most likely form a covalent bond? Na and Cl C and O N and O Si and Cl H and H

6. What do elements with atomic numbers 6, 14, and 22 have in common? same number of electrons same atomic mass same valence and will form the same number of covalent bonds all of the above none of the above

7. Living systems differ from nonliving systems in that living systems are composed largely of unusual elements. living systems are composed largely of elements with large (high) atomic numbers. living systems contain large percentages (greater than 10%) of nine elements. living systems combine simple elements in unique combinations.

8. The surface of a planet with life (a biosphere) would differ from the surface of a planet with no living organisms in that the planet with a biosphere would have unusual elements. the surface of the planet with a biosphere would have more elements with large (high) atomic numbers. the surface of the planet with a biosphere would contain large percentages of nine elements. the surface of the planet with a biosphere would have molecules that combine simple elements in unique combinations.

9. Water is a polar molecule because of the presence of ___________ bonds. ionic covalent polar covalent hydrogen More than one of the above options is correct.

10. The force of the chemical bond (the attraction between the different elements) is an electrical attraction. is a unique chemical attraction. results from the sharing of electrons. results from atoms filling their outermost valence shell.

11. Which of the following observations would distinguish between the alternative hypotheses that geckos walk on vertical surfaces via either hydrogen bonding or van der Waals interactions? Geckos can walk up dry surfaces. Geckos can walk up smooth glass surfaces—silicon dioxide is a polar, hydrophilic compound. Geckos can walk up smooth plastic surfaces— plastics are hydrophobic.