Chapter Chapter 2: The Chemical Basis of Life
 
Pre-Lab
 

1 .       Which of the following is a trace element, required only in small amounts by humans? (2.2) [Hint]

 oxygen
 iron
 nitrogen
 carbon
 hydrogen
2 .       Atoms of different phosphorus isotopes _____. (2.4) [Hint]

 have different atomic numbers
 have different numbers of neutrons
 react differently with other atoms
 have different numbers of electrons
 have different numbers of protons
3 .       How an atom behaves when it comes into contact with other atoms is determined by its _____. (2.6) [Hint]

 nucleus
 size; smaller things are more reactive
 protons
 neutrons
 electron configuration
4 .       An ionic bond is formed when _____. (2.7) [Hint]

 both atoms are equally attractive to electrons
 atoms are subjected to radioactive isotopes
 one atom transfers an electron to another atom
 both atoms are nonpolar
 both atoms are electrically neutral
5 .       Hydrogen bonding is most often seen _____. (2.9) [Hint]

 in association with ionic bonds
 when hydrogen is covalently bonded to a highly electronegative atom
 when multiple carbon atoms are present
 if the molecule consists of three or fewer atoms
 when the bonds within the molecule are nonpolar covalent bonds
6 .       Ice floats because _____. (2.13) [Hint]

 it is colder than liquid water
 its molecules are moving faster than in liquid water
 it is denser than liquid water
 its hydrogen molecules bond to the water surface film
 its water molecules are farther apart than in liquid water
7 .       Sodas typically contain sugar, flavorings, coloring agents, and carbon dioxide dissolved in water. The best term to describe this mixture would be _____. (2.14) [Hint]

 a molecule
 a solvent
 a solute
 an aqueous solution
 hydrophobic
8 .       An acid is characterized as a substance that _____. (2.15) [Hint]

 contains hydrogen
 forms covalent bonds with other substances
 donates hydrogen ions to solutions
 is a versatile solvent
 removes hydrogen ions from solutions
9 .       Most acid precipitation results from the combination of ___ with water in the atmosphere, forming acids that fall with rain or snow. (2.16) [Hint]

 sulfur and nitrogen oxides
 carbon dioxide
 ozone
 buffers
 ammonium
10 .       Which of the following is NOT a chemical reaction? (2.17) [Hint]

 Sugar and oxygen gas combine to form carbon dioxide and water.
 Sodium metal and chlorine gas (Cl2) unite to form sodium chloride.
 Hydrogen gas combines with oxygen gas to form liquid water.
 Solid ice melts to form liquid water.
 Sulfur dioxide and water vapor join to form sulfuric acid.