Chemisty Honors Ch. 2

Section 1:
-scientific method is a logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data
I.Observing and collecting data
-Observing is the use of the senses to obtain information.
-descriptive (qualitative) or numerical (quantitative)
-A system is a specific portion of matter in a given region of space that has been selected for study during an
experiment or observation

II. Formulating Hypotheses
-Generalizations are statements that apply to a range of information
-hypothesis, or testable statement.
-The hypothesis serves as a basis for making predictions and for carrying out further experiments

III. Testing Hypotheses
-During testing, the experimental conditions that remain constant are called controls, and any condition that changes is called a variable

IV. Theorizing
-A 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.
-If a model successfully explains many phenomena, it may become part
of a theory.
-A 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.

Section 2:
-Measurements represent quantities.
-A quantity is something that has magnitude, size, or amount. A quantity is not the same as a measurement.

I. SI Measurments
-SI units are defined in terms of standards of measurement. The standards are objects or natural phenomena that are of constant value, easy to preserve and reproduce, and practical in size.

II. SI Base Units
A. Mass
-mass is a measure of the quantity of matter
-SI standard unit for mass is the kilogram
-The gram (1/1000 of kilogram) ise useful for measuring mases of small objects
-milligram (1/1000 of gram & 1/000 000 of kilogram) used for even smaller objects
-Mass is often...