19
List the mass number and atomic number of carbon-12 and carbon-13, respectively.
  1. The mass number and atomic number of carbon-13 is 13 and 6, while that of cabon-12 is 12 and 6, respectively.
  2. The mass number and atomic number of carbon-13 is 13 and 12, while that of carbon-12 is 12 and 6, respectively.
  3. The mass number and atomic number of carbon-13 is 13 and 13, while that of carbon-12 is 12 and 6, respectively.
  4. The mass number and atomic number of carbon-13 is 13 and 12, while that of carbon-12 is 12 and 12, respectively.
20
Why are hydrogen bonds and van der Waals interactions necessary for cells?
  1. Hydrogen bonds and van der Waals interactions form weak associations between molecules, providing the necessary shape and structure of DNA and proteins to function in the body.
  2. Hydrogen bonds and van der Waals interactions form strong associations between molecules, providing the necessary shape and structure of DNA and proteins to function in the body.
  3. Hydrogen bonds and van der Waals interactions form weak associations between different molecules, providing the necessary shape and structure for acids to function in the body.
  4. Hydrogen bonds and van der Waals interactions form strong associations between same molecules, providing the necessary shape and structure for acids to function in the body.
21

Looking at Figure 2.7, can you infer which two groups together will form a strong ionic bond?

  1. Group 1 and Group 17
  2. Group 1 and Group 14
  3. Group 14 and Group 18
  4. Group 1 and Group 18
22
Why can some insects walk on water?
  1. Insects can walk on water because of its high surface tension.
  2. Insects can walk on water because it is a polar solvent.
  3. Insects can walk on water because they are less dense than water.
  4. Insects can walk on water because they are denser than water.
23
Discuss how buffers help prevent drastic swings in pH.
  1. Buffers absorb excess hydrogen and hydroxide ions to prevent increases or decrease in pH. An example is the bicarbonate system in human body.
  2. Buffers absorb extra hydrogen ions to prevent increases or decreases in pH. An example is the bicarbonate system in the human body.
  3. Buffers absorb excess hydroxide ions to prevent increases or decreases in pH. An example of that is the bicarbonate system in the human body.
  4. Buffers absorb excess hydrogen and hydroxide ions to prevent increases or decreases in pH. An example of that is carbonate system in human body.
24
What are three examples of how the characteristics of water are important in maintaining life?
  1. First, the lower density of water as a solid versus a liquid allows ice to float, forming an insulating surface layer for aquatic life. Second, the high specific heat capacity of water insulates aquatic life or bodily fluids from temperature changes. Third, the high heat of vaporization of water allows animals to cool themselves by sweating.
  2. First, the higher density of water as a solid versus a liquid allows ice to float, forming an insulating surface layer for aquatic life. Second, the high specific heat capacity of water insulates aquatic life or bodily fluids from temperature changes. Third, the low heat of vaporization of water allows animals to cool themselves by sweating.
  3. First, the lower density of water as a solid versus a liquid allows ice to float, forming an insulating surface layer for aquatic life. Second, the low specific heat capacity of water insulates aquatic life or bodily fluids from temperature changes. Third, the high heat of vaporization of water allows animals to cool themselves by sweating.
  4. First, the lower density of water as a solid versus a liquid allows ice to float, forming an insulating surface layer for aquatic life. Second, the low specific heat capacity of water insulates aquatic life or bodily fluids from temperature changes. Third, the low heat of vaporization of water allows animals to cool themselves by sweating.
25
Describe the pH scale and how it relates to living systems. Give an example of how drastic pH changes are prevented in living systems.
  1. The pH scale ranges from 0 to 14, where anything below 7 is acidic and above 7 is alkaline. The bicarbonate system in the human body buffers the blood.
  2. The pH scale ranges from 0 to 14, where anything below 7 is alkaline and above 7 is acidic. The bicarbonate system in human body buffers the blood.
  3. The pH scale ranges from 0 to 7, where anything below 7 is acidic and above 7 is alkaline. Water in the human body buffers the blood.
  4. pH scale ranges from 0 to 7, where anything below 4 is acidic and above 4 is alkaline. Water in the human body buffers the blood.
26

What property of carbon makes it essential for organic life?

  1. Carbon can form up to four covalent bonds, allowing it to form long chains.
  2. Carbon can form more than four covalent bonds, allowing it to form long chains.
  3. Carbon can form more than four covalent bonds, but can only form short chains.
  4. Carbon can form up to four covalent bonds, but can only form short chains.
27
What property of carboxyl makes carboxyl containing molecules hydrophilic? Which macromolecules contain carboxyl?
  1. Carboxyl groups release H+, making its parent molecule hydrophilic. It is found amino acids and fatty acids.
  2. Carboxyl groups absorb H+ ion, making its parent molecule hydrophilic. It is found in phospholipids and triglycerides.
  3. Carboxyl groups release OH−, making its parent molecule hydrophilic. It is found in phospholipids phosphates and triglycerides
  4. Carboxyl groups releaseOH−, making its parent molecule hydrophilic. It is found in phospholipids and DNA.
28
Compare and contrast saturated and unsaturated triglycerides.
  1. Saturated triglycerides contain single bonds and are solids at room temperature, while unsaturated triglycerides contain double bonds and are liquids at room temperature.
  2. Saturated triglycerides contain double bonds and are solids at room temperature, while unsaturated triglycerides contain single bonds and are liquids at room temperature.
  3. Saturated triglycerides contain single bonds and are liquids at room temperature, while unsaturated triglycerides contain double bonds and are solids at room temperature.
  4. Saturated triglycerides contain double bonds and are liquids at room temperature, while unsaturated triglycerides contain single bond and are solids at room temperature.