Chapter Preview Questions

1
Chapter Preview Questions

• 1. A chemical bond is
• a. a way of organizing elements in the
  periodic table.
• b. the force that holds two atoms together.
• c. how elements react with each other.
• d. a result of combustion.

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Chapter Preview Questions

• 1. A chemical bond is
• a. a way of organizing elements in the
  periodic table.
• b. the force that holds two atoms together.
• c. how elements react with each other.
• d. a result of combustion.

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Chapter Preview Questions

• 2. The ways in which an atom can bond with other
  atoms depends on the atoms
• a. valence electrons.
• b. nucleus.
• c. atomic number.
• d. atomic mass.

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Chapter Preview Questions

• 2. The ways in which an atom can bond with other
  atoms depends on the atoms
• a. valence electrons.
• b. nucleus.
• c. atomic number.
• d. atomic mass.

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Chapter Preview Questions

• 3. In a carbon dioxide molecule (CO2), carbon
  forms a(n)
• a. ionic compound with oxygen.
• b. atomic number.
• c. polyatomic ion.
• d. double bond with each of two oxygen
  atoms.

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Chapter Preview Questions

• 3. In a carbon dioxide molecule (CO2), carbon
  forms a(n)
• a. ionic compound with oxygen.
• b. atomic number.
• c. polyatomic ion.
• d. double bond with each of two oxygen
  atoms.

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Chapter Preview Questions

• 4. The most loosely held electrons in an atom are
• a. unstable electrons.
• b. covalent electrons.
• c. valence electrons.
• d. low-energy electrons.

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Chapter Preview Questions

• 4. The most loosely held electrons in an atom are
• a. unstable electrons.
• b. covalent electrons.
• c. valence electrons.
• d. low-energy electrons.

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Why does carbon have a central role in the
chemistry of living organisms?

• Natural gas contains mostly
• methane (CH4), a compound
• made of carbon and hydrogen.
• When methane burns, is energy
• absorbed or released?
• How do you know?

10
Section 1 Properties of Carbon

• Standard 8.6.a Students know that carbon,
  because of its ability to combine in many ways
  with itself and other elements, has a central
  role in the chemistry of living organisms.

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Carbon Atoms and Bonding

• Why does carbon play a central role in the
  chemistry of living organisms?

• Because of its unique ability to combine in many
  ways with itself and other elements, carbon has a
  central role in the chemistry of living organisms.

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Carbon Atoms and Bonding

• With four valence electrons, each carbon atom is
  able to form four bonds. Carbon atoms can form
  straight chains, branched chains, and rings.

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Carbon Atoms and Bonding

• Carbon atoms and the bonds between them can be
  modeled in several ways.

14
Forms of Pure Carbon

• What are the four forms of pure carbon?

• At very high temperatures and pressures, carbon
  atoms can form diamonds.

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Forms of Pure Carbon

• What are the four forms of pure carbon?

• Another form of the element carbon is graphite.
  In graphite, each carbon atom is bonded tightly
  to three other carbon atoms in flat layers.

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Forms of Pure Carbon

• What are the four forms of pure carbon?

• In 1985, scientists made a new form of carbon, a
  fullerene. It consists of carbon atoms arranged
  in the shape of a hollow sphere.

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Forms of Pure Carbon

• What are the four forms of pure carbon?

• In 1991, scientists made another form of carbon,
  a nanotube. It consists of carbon atoms arranged
  in the shape of a long, hollow tube.

18
Section 1 Quick Quiz

• What is the shape of pure carbon fullerenes?
• flat layers
• hard, solid crystal shaped like a ball
• hollow tube
• hollow ball with a pattern like a geodesic dome
• Answer D hollow ball with a pattern like a
  geodesic dome

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Section 1 Quick Quiz

• Which form of pure carbon is formed of layers
  that slide past one another?
• graphite
• diamond
• fullerene
• nanotube
• Answer A - graphite

20
Section 1 Quick Quiz

• How many chemical bonds can each carbon atom
  form?
• one
• two
• three
• four
• Answer D - four

21
Section 1 Quick Quiz

• Which form of pure carbon is so hard that it can
  be used in cutting tools?
• graphite
• diamond
• nanotube
• fullerene
• Answer B - diamond

22
Section 1 Quick Quiz

• In a nanotube, carbon atoms are arranged in
• the shape of a hollow sphere.
• the shape of a spiral ladder.
• the shape of a long, hollow cylinder.
• flat layers.
• Answer C the shape of a long, hollow cylinder

23
Section 1 Quick Quiz

• Carbon is able to bond with atoms of other
  elements in many different ways because it has
• four valence electrons.
• six valence electrons.
• six protons.
• four electrons.
• Answer A four valence electrons

24
Section 2 Carbon Compounds

• Standard 8.3.c Students know atoms and molecules
  form solids by building up repeating patterns,
  such as the crystal structure of NaCl or
  long-chain polymers.
• Standard 8.6.a Students know that carbon,
  because of its ability to combine in many ways
  with itself and other elements, has a central
  role in the chemistry of living organisms.

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Organic Compounds

• What are some similar properties shared by
  organic compounds?
• organic compounds

• Many organic compounds have similar properties in
  terms of melting points, boiling points, odor,
  electrical conductivity, and solubility.
• Carbon compounds are so numerous that they are
  given a specific name. With some exceptions,
  compounds that contain carbon are called organic
  compounds.

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Organic Compounds

• What are some properties of hydrocarbons?
• hydrocarbon

• Like many other organic compounds, hydrocarbons
  mix poorly with water. Also, all hydrocarbons
  are flammable.
• A compound that contains only the elements carbon
  and hydrogen.
• Examples
• Methane CH4 (natural gas)
• Ethane C2H6
• Propane C3H8

27
Structure and Bonding in Hydrocarbons

• What kind of structures and bonding do
  hydrocarbons have?
• Structural Formula

• The carbon chains in a hydrocarbon may be
  straight, branched, or ring-shaped.
• A structural formula shows the kind, number, and
  arrangement of atoms in a molecule.

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Boiling Points of Hydrocarbons

• The graph shows the boiling points of several
  hydrocarbons. (Note Some points on the y-axis
  are negative.)
• Use the graph to answer the following questions.

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Boiling Points of Hydrocarbons

• Reading Graphs
• Where is 0ºC on the graph?

• Almost in the center of the y-axis

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Boiling Points of Hydrocarbons

• Interpreting Data
• What is the approximate boiling point of C3H8?
  C5H12? C6H14?

• C3H8 about 44ºCC5H12 about 34ºCC6H14
  about 68ºC

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Boiling Points of Hydrocarbons

• Calculating
• What is the temperature difference between the
  boiling points of C3H8 and C5H12?

• About 78ºC

32
Boiling Points of Hydrocarbons

• Drawing Conclusions
• At room temperature (about 22ºC), which of the
  hydrocarbons are gases? How can you tell?

• C2H6, C3H8, and C4H10 are gases because their
  boiling points are below room temperature (about
  22ºC). C5H12 and C6H14 may be liquids or solids,
  depending on their melting points.

33
Structure and Bonding in Hydrocarbons

• Compounds that have the same chemical formula but
  different structural formulas are called isomers.
  Each isomer is a different substance with its own
  characteristic properties.

34
Structure and Bonding in Hydrocarbons

• In addition to forming a single bond, two carbon
  atoms can form a double bond or a triple bond.

35
Structure and Bonding in Hydrocarbons

• Saturated hydrocarbons
• Unsaturated hydrocarbons

• Hydrocarbons with only single bonds that have the
  maximum number of hydrogen atoms possible on
  their carbon chains
• Hydrocarbons with double or triple bonds that
  have fewer hydrogen atoms for each carbon atom
  than saturated hydrocarbons.
• In general, a chain hydrocarbon ending in ane is
  saturated. A chain hydrocarbon ending in ene or
  yne is unsaturated.

36
Structure and Bonding in Hydrocarbons

• What are some characteristics of substituted
  hydrocarbons?

• If just one atom of another element is
  substituted for a hydrogen atom in a hydrocarbon,
  a different compound is created.
• A hydrocarbon in which one or more hydrogen atoms
  have been replaced by atoms of other elements.
• Substituted hydrocarbons include
  halogen-containing compounds, alcohols, and
  organic acids.

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Substituted Hydrocarbons

• Alcohols
• When a hydroxyl group (-OH) is substituted for a
  hydrogen atom in methane (CH4), methanol is
  formed.

• A hydroxyl group (OH) is made of an oxygen atom
  and a hydrogen atom. An alcohol is a substituted
  hydrocarbon that contains one more more hydroxyl
  groups.

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Substituted Hydrocarbons

• Organic Acids

• An organic acid is a substituted hydrocarbon that
  contains one or more carboxyl groups. A carboxyl
  group is written as COOH.

39
Esters

• What are some characteristics of esters?

• An ester is a compound made by chemically
  combining an alcohol and an organic acid.
• Esters are responsible for the smells of
  pineapples, bananas, strawberries, and apples.

40
Polymers

• What are some characteristics of polymers?

• A polymer is a very large molecule made of a
  chain of many smaller molecules bonded together.
• The smaller molecules are called monomers.
• Organic compounds, such as alcohols, esters, and
  others, can be linked together to build polymers
  with thousands or even millions of atoms.

41
Section 2 Quick Quiz

• What is another name for carbon compounds?
• hydrocarbons
• fullerenes
• organic compounds
• carbohydrates
• Answer C organic compouns

42
Section 2 Quick Quiz

• Compounds that contain only the elements carbon
  and hydrogen are called
• isomers.
• carbon chains.
• substituted hydrocarbons.
• hydrocarbons.
• Answer D - hydrocarbons

43
Section 2 Quick Quiz

• What can you tell about methane (CH4) from its
  molecular formula?
• It contains four hydrogen atoms.
• It contains four carbon atoms.
• It forms groups of four molecules.
• It contains one hydrogen atom.
• Answer A It contains four hydrogen atoms.

44
Section 2 Quick Quiz

• What property do all hydrocarbons have?
• They dissolve in water.
• They make good conductors of electricity.
• They have high melting points.
• They burn easily.
• Answer D They burn easily.

45
Section 2 Quick Quiz

• Butane and isobutane have the same chemical
  formula (C4H10). However, butane is a straight
  chain, whereas isobutane is a branched chain.
  Butane and isobutane are examples of
• monomers.
• isomers.
• substituted hydrocarbons.
• unsaturated hydrocarbons.
• Answer B - isomers

46
Section 2 Quick Quiz

• The alcohol methanol (CH4OH) forms when one of
  the hydrogen atoms in methane (CH4) is replaced
  with a hydroxyl group (-OH). Alcohols are
  examples of
• carbohydrates.
• esters.
• substituted hydrocarbons.
• unsaturated hydrocarbons.
• Answer C substituted hydrocarbons

47
Section 2 Quick Quiz

• A very large organic molecule made up of chains
  of smaller molecules is called a
• substituted hydrocarbons.
• polymer.
• monomer.
• saturated hydrocarbon.
• Answer B - polymer

48
Section 3 Polymers and Composites

• Standard 8.3.c Students know atoms and molecules
  form solids by building up repeating patterns,
  such as the crystal structure of NaCl or
  long-chain polymers.

49
Forming Polymers

• How do polymers form?

• Polymers form when chemical bonds link large
  numbers of monomers in a repeating pattern.

50
Polymers and Composites

• Natural Polymers

• Plants, animals, and other living things produce
  many natural materials made of large polymer
  molecules.
• Cellulose is a flexible but strong natural
  polymer found in the cell walls of fruits and
  vegetables.
• Proteins are polymers formed from smaller
  molecules called amino acids.

51
Polymers and Composites

• Synthetic Polymers

• The properties of synthetic polymers make them
  ideal starting materials for many common objects.
• The starting materials for many synthetic
  polymers come from coal or oil.
• Plastics are the most common synthetic polymers.

52
Polymers and Composites

• What are composites made of?

• Many composites include one or more polymers.
• A composite combines two or more substances in a
  new material with different properties.
• Wood is a natural composite made of cellulose and
  lignin. The two polymers are weak by themselves,
  but they are strong when combined together.

53
Recycling Plastics

• How can you help reduce the amount of plastic
  waste?

• You can help reduce the amount of plastic waste
  by recycling.
• Plastics do not react very easily with other
  substances, so they do not degrade into simpler
  materials in the environment.

54
Section 3 Quick Quiz

• Which of the following is a polymer formed from
  smaller molecules called amino acids?
• ester
• protein
• starch
• cellulose
• Answer B - protein

55
Section 3 Quick Quiz

• Wood is a natural composite made of two plant
  polymers, lignin and cellulose. Without
  cellulose, a tree branch would probably
• be as hard as steel.
• be made of denser wood.
• bend more easily in the wind.
• snap more easily.
• Answer D snap more easily

56
Section 3 Quick Quiz

• Which of the following statements about synthetic
  polymers is NOT true?
• Synthetic polymers last a long time.
• Synthetic polymers are inexpensive to make.
• Synthetic polymers react easily with other
  substances.
• Synthetic polymers increase the volume of trash.
• Answer C Synthetic polymers react easily with
  other substances.

57
Section 4 Life With Carbon

• Standard 8.6.b Students know that living
  organisms are made of molecules consisting
  largely of carbon, hydrogen, nitrogen, oxygen,
  phosphorus, and sulfur.
• Standard 8.6.c Students know that living
  organisms have many different kinds of molecules,
  including small ones, such as water and salt, and
  very large ones, such as carbohydrates, fats,
  proteins, and DNA.

58
Life With Carbon

• What are four classes of organic compounds
  required by living things, and how are they used
  in the body?
• Carbohydrates
• Proteins

• The four classes of organic compounds required by
  living things are carbohydrates, proteins,
  lipids, and nucleic acids.
• The body breaks down starch into glucose, which
  is used by the body as energy to carry out its
  life functions.
• The body uses proteins from food to build and
  repair body parts and to regulate cell
  activities.

59
Life With Carbon

• Lipids

• Gram for gram, lipids release twice as much
  energy in your body as do carbohydrates.
• Lipids include fats and oils. Fats are usually
  solid at room temperature, whereas oils are
  liquid.
• Cholesterol is a lipid used by the body to build
  cell structures and to form important compounds.
  An excess of cholesterol in the blood can
  contribute to heart disease.
• Cholesterol is often found in the same foods as
  saturated fats.
• Saturated fats can affect the level of
  cholesterol in the blood.

60
Life With Carbon

• Nucleic Acids

• There are two types of nucleic acids, DNA and
  RNA.
• DNA is made from four kinds of nucleotides.
• RNA is also made from four kinds of nucleotides,
  but the nucleotides in RNA differ from those in
  DNA.
• The differences among living things depend on the
  order of nucleotides in their DNA.
• When living things reproduce, they pass DNA and
  the information it carries to the next generation.

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Other Nutrients

• Why do organisms need water, vitamins, minerals,
  and salts?
• Water
• Vitamins
• Minerals
• Salts

• Organisms require water, vitamins, minerals, and
  salts to support the functioning of large
  molecules.
• Water makes up about 90 percent of the liquid
  part of blood. Nutrients are dissolved in the
  watery part of blood and carried throughout the
  body.
• Vitamins serve as helper molecules in a variety
  of chemical reactions in the body.
• Minerals are elements in the form of ions needed
  by the body.
• Salts are ionic compounds that help the body in
  such processes as muscle contraction, bone
  growth, and pH balance.

62
The Molecules of Life

• Complex carbohydrates, proteins, lipids, and
  nucleic acids are all large organic molecules.
  They are built of smaller molecules linked in
  different patterns.

63
Section 4 Quick Quiz

• Substances that provide the energy and raw
  materials the human body needs are
• nutrients.
• substituted hydrocarbons.
• esters.
• unsaturated hydrocarbons.
• Answer A - nutrients.

64
Section 4 Quick Quiz

• The classes of organic compounds found in all
  living things are
• halogen compounds, alcohols, organic acids, and
  esters.
• carbohydrates, lipids, proteins, and nucleic
  acids.
• vitamins and minerals.
• simple carbohydrates and hydrocarbons.
• Answer B carbohydrates, lipids, proteins, and
  nucleic acids.

65
Section 4 Quick Quiz

• Which organic compound carries information from
  one generation to the next during reproduction?
• carbohydrates
• lipids
• proteins
• DNA
• Answer D - DNA

66
Section 4 Quick Quiz

• Gram for gram, which organic compounds release
  twice as much energy in your body as do
  carbohydrates?
• vitamins
• lipids
• proteins
• nucleic acids
• Answer B - lipids