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13 Cards in this Set
- Front
- Back
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chemistry |
the study of the composition, structure, and properties of matter, and the changes that matter undergoes
example: chemistry is everywhere-fertilizer, sunscreen, baking, firefighting |
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matter |
anything that occupies space and has mass |
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atoms |
the smallest possible particles of a substance that are recognizable as that substance |
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scientific method |
the process of proposing and testing; there are five steps to the process |
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step 1: define the problem |
before any experiment can be conducted or any problem can be solved, a specific question or problem must be defined |
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step 2: gather information |
you need as much information as possible to solve a problem; information can be gathered through observing nature, reading related research, communicating with experts
example: Louis Pasteur looked at sweet and sour wines under a microscope |
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step 3: hypothesis |
a possible explanation for the gathered information
example: Pasteur's hypothesis was that germs in the sour wine were the cause of the sourness |
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step 4: experiment |
a controlled experiment to test the validity of a hypothesis
example: Pasteur divided a barrel of sweet wine into two casks and added the germs to one cask; the sweet wine stayed sweet, the one with the germs turned sour |
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step 5: theory |
develop an idea that is based on experimental results; a theory attempts to explain experimental results already obtained and to predict results not yet obtained
example: Pasteur concluded from his experiments that his hypothesis was correct and predicted that germs may cause diseases |
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flowchart of the scientific method |
1. define the problem > 2. gather information > 3. propose a hypothesis > 4. conduct an experiment > 5. develop a theory |
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Pasteur's experiments with wine lead to our pasteurization of milk, what does that do to milk? |
milk is heated to a temperature that kills harmful germs but does not greatly change its chemical makeup |
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Can a theory be proved? |
Experiments can disprove a theory, but they cannot prove one. A theory is not a fact. Experiments can support a theory but new experiments can disprove the theory.
example: Pasteur's theory was validated by other scientists' experiments, and some scientists contradicted Pasteur's theory in some ways. |
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What happens when evidence is found to contradict a theory? |
When this happens, a theory must be discarded or changed to match the new experimental results. Experimental results must never be changed to match a theory. It is common for scientists to repeats experiments several times in order to be sure the results are consistent and reproducible and can be repeated by someone else with the same result. |
