scientific method - a logical problem-solvingtechnique that requires reasoning, skepticism, and
direction. It is used to discover the truth by confirming (or rejecting hypotheses, thoughts, and ideas.
null hypothesis - states that the expected cause (ind. var.) has no effect on the outcome (dep. var.)
hypothesis - a rational explanation of a phenomenon that has not been proven; it is the starting point
for scientific experimentation and is an empirically testable conjecture.
theory - an explanation of a natural phenomenon supported by many observations and experiments; it
is a scientifically supported explanation regarding a phenomenon at the current level of understanding,
and may be used to make useful predictions. These are explanations that are in need of replication and
verification by other knowledgeable scientists working in the same area.
fact - something that is always true. In science, these are verifiable and are verified by repeated
experiments conducted by different researchers who yield the same data.
scientific law - a formal scientific statement that describes a phenomenon that has been scientifically
proven to absolutely and invariably occur under given conditions. These are led to be true and universal
statements of fact meant to describe phenomena
models - simplified substitutes that make concepts or processes easier to visualize and understand.
scientific design - a procedure to create a fair test of a hypothesis. a completely fair test is one that
shows no bias or favoritism toward any variable, whether controlled or uncontrolled, within the
experiment.
experimental design - the blueprint of the procedure for a fair test of a hypothesis. This yields unbiased
data from which a conclusion is drawn regarding the relationship between the independent and
dependent variables. It is the logical and complete conceptual framework for an experiment and must
be completed before the experiment begins.
,problem statement - a clear definition of the problem to be investigated. The hypothesis is based on
this.
independent variable - the factor being tested and is manipulated by the researcher.
dependent variable - a measurement of the independent variable
test group - the selected participants in the group that is in keeping with the intent of the independent
variable
control group - a subset of the target group, and is used as a comparison to show any changes in the
target group that occurred because of the independent variable. Once established, the remainder of the
target group becomes the treatment group.
treatment group - the population that will receive the independent variable "treatment"
uncontrolled variables - a major source of experimental error and may render the data useless
SI Units - how measurements in science are expressed---typically metric
base units - what SI is built upon. These define the unit absolutely and do not require referencing other
units. These are then combined with SI prefixes to make the unit of measure smaller or larger
precision - refers to how close several measured values are to each other
accuracy - how close the measured values are to the true or actual value
charts - refine raw data into an organized format
graphs - there are many of these used in science; the three most common are line, bar, and pie
, percent error - compares experimental results with a known or expected value
experimental error - occurs in most student experiments and comprises the concept of a fair test of the
hypothesis
Material Safety Data Sheet (MSDS) - on file in a lab, this helps teachers know the proper use, storage,
and disposal of chemicals.
inventory - includes a list of chemicals, dates, and amounts for a lab
solid - has a definite volume and does not need a container to maintain its shape. The structure of these
can be either crystalline or amorphous.
crystalline solid - has a regular and repeating arrangement of particles, such as atoms, ions, or
molecules. The four types include: ionic, molecular, network, and metallic.
amorphous solid - has no regular or repeating arrangement of particles, has definite volume, and does
not need a container to maintain its shape
heat of fusion - the amount of energy needed to overcome the intermolecular forces (IMF) that hold the
substance together as a solid
vapor pressure - is exerted by gas molecules when in equilibrium with its liquid phase
viscosity - the resistance of a liquid to flow
surface tension - a measure of the resistance of a liquid to spread out
Boyle's Law - states that for a fixed amount of an ideal gas at a given temperature, the pressure and
volume of that gas are inversely related: P1V1=P2V2
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller oneclass. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.48. You're not tied to anything after your purchase.