Chapter 1: Chemistry: the central science
1. Chemistry: • The study of matter and the changes it undergoes
• often called central science
2. Matter: • Anything that occupies space and has mass.
3. Ball and stick model: • model where the bonds connecting atoms appear as
sticks
• does a good job of illustrating the arrangement of atoms, but exaggerates the
distances between atoms, relative to their sizes
4. Space-filling model: • model where the atoms appear to overlap one another •
gives a more accurate picture of these interatomic distances but can obscure
the details of the three-dimensional arrangement.
5. Scientific Method: • A systematic approach to experimentation
• begins with the gathering of data via observations and experiments. Scientists
study these data and try to identify patterns or trends
• When they find a pattern or trend, they may summarize their findings with a law
• Scientists may then formulate a hypothesis
• If experiments indicate that the hypothesis is incorrect, the scientists go back to
the drawing board, try to come up with a different interpretation of their data, and
formulate a new hypothesis. The new hypothesis will then be tested by
experiment. When a hypothesis stands the test of extensive experimentation, it
may evolve into a theory.
• Theories can also be used to predict related phenomena, so theories are
constantly being tested. If a theory is disproved by experiment, then it must be
discarded or modified so that it becomes consistent with experimental
observations.
6. Law: A concise verbal or mathematical statement of a reliable relationship
between phenomena
7. Hypothesis: A tentative explanation for a set of observations
8. Theory: A unifying principle that explains a body of experimental observations
and the laws that are based on them
9. Substance: • Matter with a definite (constant) composition and distinct
properties
• salt (sodium chloride), iron, water, mercury, carbon dioxide, and oxygen
• can be further classified as either elements (such as iron, mercury, and oxygen)
or compounds (such as salt, water, and carbon dioxide)
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1. Chemistry: • The study of matter and the changes it undergoes
• often called central science
2. Matter: • Anything that occupies space and has mass.
3. Ball and stick model: • model where the bonds connecting atoms appear as
sticks
• does a good job of illustrating the arrangement of atoms, but exaggerates the
distances between atoms, relative to their sizes
4. Space-filling model: • model where the atoms appear to overlap one another •
gives a more accurate picture of these interatomic distances but can obscure
the details of the three-dimensional arrangement.
5. Scientific Method: • A systematic approach to experimentation
• begins with the gathering of data via observations and experiments. Scientists
study these data and try to identify patterns or trends
• When they find a pattern or trend, they may summarize their findings with a law
• Scientists may then formulate a hypothesis
• If experiments indicate that the hypothesis is incorrect, the scientists go back to
the drawing board, try to come up with a different interpretation of their data, and
formulate a new hypothesis. The new hypothesis will then be tested by
experiment. When a hypothesis stands the test of extensive experimentation, it
may evolve into a theory.
• Theories can also be used to predict related phenomena, so theories are
constantly being tested. If a theory is disproved by experiment, then it must be
discarded or modified so that it becomes consistent with experimental
observations.
6. Law: A concise verbal or mathematical statement of a reliable relationship
between phenomena
7. Hypothesis: A tentative explanation for a set of observations
8. Theory: A unifying principle that explains a body of experimental observations
and the laws that are based on them
9. Substance: • Matter with a definite (constant) composition and distinct
properties
• salt (sodium chloride), iron, water, mercury, carbon dioxide, and oxygen
• can be further classified as either elements (such as iron, mercury, and oxygen)
or compounds (such as salt, water, and carbon dioxide)
1/3
