Study Guide

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Chapter 4.3
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Study Guide

• Source
• Campbell, N.A., Williamson, B., and Heyden, R.J.
  (2004) Biology Exploring Life. Upper Saddle
  River, New Jersey Pearson Education, Inc.,
  Chapter 4.

3
Q1ion
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A1ion

• an atom that has become electrically charged as
  a result of gaining or losing an electron

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Q2ionic bond
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A2 ionic bond

• An ionic bond is a chemical bond that occurs
  when an atom transfers an electron to another
  atom.
• The attraction between to oppositely charged
  holds the two ions together in an ionic bond.

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Q3Covalent bond
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A3 Covalent bond

• Covalent bonds form when two atoms share
  electrons.
• The number of covalent bonds an atom can form
  usually equals the number of electrons needed to
  fill its highest occupied energy level.

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Q4molecule
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A4 molecule

• A molecule is two or more atoms held together by
  a covalent bond.

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Q5Chemical reaction
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A5 Chemical reaction

• A chemical reaction occurs when chemical bonds
  break and new bonds form, producing one or more
  new substances.
• A chemical equation describes a chemical reaction

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Q6Reactants
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A6 Reactants

• Reactants are the starting materials in a
  chemical reaction.

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Q7Products
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A7 Products

• Products are the ending materials in a chemical
  reaction.

17
Q8Contrast an ionic bond and a covalent bond.
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A8 Contrast an ionic bond and a covalent bond.

• An ionic bond is a chemical bond that occurs
  when an atom transfers an electron to another
  atom.
• A covalent bond forms when two atoms share
  electrons.

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Q9What is a molecule?
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A9 What is a molecule?

• A molecule is two or more atoms held together by
  a covalent bond.

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Q10What happens in a chemical reaction?
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A10 What happens in a chemical reaction?

• In a chemical reaction chemical bonds break and
  new bonds form.

23
Q11Describe how an ionic bond forms. How is this
process different from the formation of a
covalent bond?
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A11Describe how an ionic bond forms. How is this
process different from the formation of a
covalent bond?

• An ionic bond forms when oppositely charged ions
  formed from the transfer of electrons are
  attracted to one another.
• In a covalent bond, no transfer of electrons
  occurs. Instead, electrons are shared between
  atoms.

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Q12In a molecule represented by the chemical
formula C6H12O6 , how many atoms of each element
are present?
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A12In a molecule represented by the chemical
formula C6H12O6 , how many atoms of each element
are present?

• Carbon6
• Hydrogen 12
• Oxygen 6

27
Q13What information does a chemical equation
provide about a chemical reaction?
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A13 What information does a chemical equation
provide about a chemical reaction?

• A chemical equation identifies the reactants and
  the products of a reaction and gives the chemical
  formula of each substance.

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Q14A carbon atom has 4 electrons in its highest
energy level. How many hydrogen atoms could
become bonded to a single carbon atom?
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A14A carbon atom has 4 electrons in its highest
energy level. How many hydrogen atoms could
become bonded to a single carbon atom?

• Four hydrogen atoms can bond with one carbon
  atom.

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Q15What happens in a chemical reaction?
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A15 What happens in a chemical reaction?

• In a chemical reaction chemical bonds break and
  new bonds form.