Elements, Compounds, and Mixtures

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Chapter 4

• Elements, Compounds, and Mixtures

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Elements

• An ___________ is a pure substance that cannot be
  separated into simpler substances by physical or
  chemical means.
• A _______ __________is a substance in which
  there is only one type of particle.
• These particles are called ________.
• Atoms of different elements are different.
• Atoms of the same element are the same.

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Properties of Elements

• Each element has its own ________________
  properties.
• These properties do _____ depend on the amount of
  the element present.
• Characteristic properties include ___________
  point, _________ point, _________, reactivity.

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Example
If cobalt and nickel share the same density, 8.9
g/cm3, what other characteristic properties would
distinguish these elements?
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Classifying Elements

• There are three categories of elements
• ________ elements that are shiny (lustrous),
  good conductors, malleable, ductile, on the left
  side of the Periodic Table

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Nonmetals

• _______________ elements that are poor
  conductors, brittle, dull, on the right side of
  the Periodic Table

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Metalloids

• ______________ elements that have
  characteristics of both metals and nonmetals,
  located along the line

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Compounds

• A compound is a pure substance composed of ______
  or more elements ____________ combined.
• The smallest particle of a compound is a
  ___________.
• Molecules of compounds are formed when atoms of
  two or more elements chemically join together.

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Figure 1 Page 94

• In this figure, magnesium is burning and
  combining with oxygen.
• Magnesium oxide is formed.
• ___________ and _________ have undergone a
  chemical change.
• Magnesium oxide is a compound with ___________
  properties than either magnesium or oxygen.

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Table 1 Familiar Compounds

• According to this table, what elements combine to
  form table salt?
• ___________ and ____________
• What elements combine to form water?
• ___________ and __________

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Table 1 Cont

• What compound is formed from a chemical
  combination of sodium, hydrogen, carbon, and
  oxygen?
• __________ _________

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Ratio of Elements in a Compound

• Elements join to form compounds in a specific
  ratio.
• The ratio of the mass of hydrogen to the mass of
  oxygen in water is 18.
• Every sample of water has the same ratio.
• What would happen if a sample of a compound has a
  different mass ratio of hydrogen to oxygen?
• ______ _________ _______ ______ ___ _______

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Properties of Compounds

• Each compound has its own _____________
  properties.
• Compounds can be identified by physical
  properties such as density and melting point, as
  well as chemical properties such as reactivity.
• Properties of the elements are ______ the same as
  the properties of the compounds they make.

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Breaking Down Compounds

• The only way to break down a compound is through
  a _________ _________.
• Compounds can break down into the elements they
  are made of, or they can be broken down into
  simpler compounds.
• Ex. Glucose C6H12O6 can be broken down into
  carbon dioxide (CO2) and water (H2O).

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