Chapter 1 Chemistry: The Study of Matter

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Chemistry The Study of Matter
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What is Chemistry?

• The study of the matter, its composition,
  properties, and the changes it undergoes.
• Applied Chemistry is the using chemistry to
  attain certain goals, in fields like medicine,
  agriculture, and manufacturing
• Pure chemistry gathers knowledge for knowledge
  sake

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Types of Chemistry

• Analytical Chemistry studies composition of
  substances.
• Inorganic Chemistry substances without carbon
• Organic Chemistry compounds containing carbon
• Biochemistry- Chemistry of living things
• Physical Chemistry studies behavior of substances

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Scientific Method

• A way of solving problems or answering questions.
• Starts with observation- noting an recording
  facts
• Hypothesis- an educated guess as to the cause of
  the problem or answer to the question.

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Scientific Method

• Experiment- designed to test the hypothesis
• There are only two possible answers!
• hypothesis is right
• hypothesis is wrong
• Generates data observations from experiments.
• Modify hypothesis - repeat the cycle

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• Outcome 1
• Cycle repeats many times.
• The hypothesis gets more and more certain.
• Becomes a theory
• A thoroughly tested model that explains why
  things behave a certain way.

Observations
Hypothesis
Experiment
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• Outcome 2
• Theory can never be proven.
• Useful because they predict behavior
• Help us form mental pictures of processes (models)

Observations
Hypothesis
Experiment
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• Outcome 3
• Another outcome is that certain behavior is
  repeated many times
• Scientific Law is developed
• Description of how things behave
• Law - how
• Theory- why

Observations
Hypothesis
Experiment
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Observations
Hypothesis
Experiment
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What is Matter?
Matter anything that takes up space (volume)
and has a mass.
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Chemical vs. Physical Properties
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Physical Properties

• a property that can be observed and measured
  without changing the composition of the
  substance.
• Examples
• densities, melting points, boiling points,
  freezing points, color or smells, luster,
  malleability, conductivity, hardness, solubility

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Chemical Properties

• a property that can only be observed by changing
  the composition of the substance which occurs
  during a chemical change
• (a loss of the identity of the substance - a new
  substance is produced).
• A good example of chemical properties is the way
  elements combine with each other in reactions

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Physical vs Chemical Changes

• Physical changes - a change that changes
  appearances, without changing the composition
  the reverse is possible
• ex Boiled water is still water.
• Chemical changes - a change where a new form of
  matter is form
• ex rusting of iron

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States of Matter

• Solid definite shape, molecules close together,
  rigid formation, little molecular movement,
  vibration

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• Liquid indefinite shape, molecules further
  apart than solids, more molecular movement
• Pressure and temperature influence it.

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• Gas indefinite shape and formation.
• Molecules are far apart.
• The most molecular movement, constant motion
• Affected by temperature and pressure

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States of Matter
Definite Volume?
Definite Shape?
Temperature increase
Compressible?
Small Expansion
Solid
YES
YES
NO
Small Expansion
Liquid
NO
NO
YES
Large Expansion
Gas
NO
NO
YES
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Liquid
Gas
Solid
Sublimation