Academic Chemistry
Mr. Gensits
Class Notes 2/1/2016
Alchemy
Long before there were chemists, alchemists were studying
matter. Alchemy had a practical side and a mystical side.
Practical alchemy focused on developing techniques for working
with metals, glass and dyes.
Alchemists developed tools and techniques for working with
chemicals. Alchemists developed processes for separating
mixtures and purifying chemicals. They designed equipment used
today, including beakers, flasks, tongs, funnels and the mortar
and pestle. What they did not provide was a logical set of
explanations for the changes in matter that they did observe.
The Experimental Approach to Science
In the 1500’s in Europe, there was a shift from alchemy to science.
Scientists met to discuss scientific concepts and conduct experiments. In
France, Antoine-Laurent Lavoisier did work in the late 1700’s that would
revolutionize the science of chemistry. Lavoisier helped transform
chemistry from a science of observation to the science of measurement that
it is today.
The Scientific Method
The scientific method is a logical, systematic approach to the
solution of a scientific problem.
Hypothesis
A proposed, but unproved, explanation of observed facts.
Experiment
A carefully devised procedure for making observations and
gathering data.
An experiment is a procedure that is used to test a
hypothesis or theory.
For the results of an experiment to be accepted, the
experiment must produce the same result no matter how
many times it is repeated, or by whom.
Manipulated (Independent) Variable – the variable that you
change during an experiment
Responding (Dependent) Variable – the variable that is
observed during an experiment.
Observation
A fact or occurrence that is noticed, usually as an early part
of the scientific method.
Qualitative Observation
An observation that describes phenomena without the use of
measurement.
Quantitative Observation
An observation that involves a numerical measurement.
Scientific Theory
A logical and time-tested explanation for a broad set of
observations. Once a hypothesis meets the test of
repeated experimentaion, it may be raised to a higher level
of ideas – a theory.
Scientific Law
A concise statement that summarizes the results of many
observations and experiments.
Scientific laws describe natural phenomena.
Scientific theories attempt to explain phenomena.