Section 1: Scientific Method Flashcards
(27 cards)
The Scientific Method Chronological Process
Observation Ask Questions Formulating a Hypothesis "if-then" Controlled Experiment (testing hypothesis) Drawing a Conclusion
scientific method
is a logical approach to solving problems by observing and col- lecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data
Observing
is the use of the senses to obtain information, and involves making measurements and collecting data.
data
may be descriptive (qualitative) or numerical (quantitative) in nature.
Ex. Numerical information, such as the fact that a sample of copper ore has a mass of 25.7 grams, is quantitative.
Non-numerical information, such as the fact that the sky is blue, is qualitative.
Experimenting involves
carrying out a procedure under controlled conditions to make observations and collect data
To learn more about matter, chemists study
Systems
Generalizations
Generalizations are statements that apply to a range of information. Scientists use generalizations about the data to formulate a hypothesis, or testable statement.
To make generalizations…
data are sometimes organized in tables and analyzed using statistics or other mathematical techniques, often with the aid of graphs and a computer.
hypothesis serves as…
as a basis for making predictions and for carrying out further experiments.
Hypotheses are often drafted as…
“if-then” statements. The “then” part of the hypothesis is a prediction that is the basis for testing by experiment.
Testing a hypothesis requires…
experimentation that provides data to support or refute a hypothesis or theory
During testing, the experimental conditions that remain constant are called
Controls
variable
any condition that changes. Any change observed is usually due to the effects of the variable.
If testing reveals that the predictions were not correct, the hypothesis on which the predictions were based must be
Discarded or modified (reject or revise)
When the data from experiments show that the predictions of the hypothesis are successful, scientists typically try to explain the phenomena they are studying by
Constructing a model
model
in science is more than a physical object; it is often an explanation of how phenomena occur and how data or events are related. (visual, verbal, or mathematical)
Ex. One important model in chemistry is the atomic model of matter, which states that matter is composed of tiny particles called atoms.
theory
is a broad generalization that explains a body of facts or phenomena.
Theories are considered successful if they can predict the results of many new experiments.
Ex. The atomic model is a part of the atomic theory; kinetic-molecular theory and collision theory
system
is a specific portion of matter in a given region of space that has been selected for study during an experiment or observation
Ex. When you observe a reaction in a test tube, the test tube and its contents form a system.
How does a quantity differ from a unit? Use to example to explain the difference?
The quantity is the “how much” of something. The unit of measure is the word used to describe how much. For example. I am 6 feet tall. The 6 is the quantity and the feet is the measuring unit.
What is a derived unit?
A unit that can be obtained from combinations of fundamental units
What is the SI-derived unites for area?
The square meter (m2)
List two SI-derived unites for volume.
Cubic meter, cubic centimeter
List two non-SI unties for volume, and explain who they relate to the cubic centimeter.
liter = 1000 cm3, milliliter is equal to 1 cm3
Why are the unites used to express the densities of gasses different from those used to express the densities of solids or liquids?
Smaller unites are used because gases are less dense
