what is science? science is a pursuit of knowledge about how the world works scientific data is...
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What Is Science?
• Science is a pursuit of knowledge about how the world works
• Scientific data is collected by making observations and taking measurements
• Observations involve the five senses, and help answer questions or problems
Observation• QualitativeQualitative
– of, relating to, or involving quality or kind
– ie.: red, hot, burns quickly, etc.
• QuantitativeQuantitative– of, relating to, or
involving the measurement of quantity or amount
– ie.: 350 degrees Celsius, 5 inches, etc.
Inference1. To conclude from evidence
or premises
2. To reason from circumstance; surmise: We can infer that his motive in publishing the diary was less than honorable
3. To lead to as a consequence or conclusion: “Socrates argued that a statue inferred the existence of a sculptor”
Vocabulary
• Experiment – A procedure to study a phenomenon
under known conditions – Must have a Control
• Hypotheses – A possible explanation of something
observed in nature.
• Model – An approximate representation of a
system being studied.
Theory and Law
• Scientific Theory – A hypothesis that has been supported by
multiple scientists’ experiments in multiple locations
• A Scientific Law – a description of what we find happening in
nature over and over again in a certain way
Experiments
• Variables are what affect processes in the experiment.
• Controlled experiments have only one variable
• Experimental group gets the variable
• Control group does not have the variable– Placebo is a harmless pill
that resembles the pill being tested.
– In double blind experiments, neither the patient nor the doctors know who is the control or experiment group.
TYPES AND STRUCTURE OF MATTER
• Elements and Compounds– Matter exists in chemical
forms as elements and compounds.
• Elements (represented on the periodic table) are the distinctive building blocks of matter.
• Compounds: two or more different elements held together in fixed proportions by chemical bonds.
Ions
• An ion is an atom or group of atoms with one or more net positive or negative electrical charges.
• The number of positive or negative charges on an ion is shown as a superscript after the symbol for an atom or group of atoms
– Hydrogen ions (H+), Hydroxide ions (OH-)
– Sodium ions (Na+), Chloride ions (Cl-)
• The pH (potential of Hydrogen) is the concentration of hydrogen ions in one liter of solution.
Figure 2-5Figure 2-5
Organic Compounds: Carbon Rules
• Organic compounds contain carbon atoms combined with one another and with various other atoms such as H+, N+, or Cl-.
• Contain at least two carbon atoms combined with each other and with atoms.
– Methane (CH4) is the only exception.
– All other compounds are inorganic.
Organic Compounds: Carbon Rules
• Hydrocarbons: compounds of carbon and hydrogen atoms (e.g. methane (CH4)).
• Chlorinated hydrocarbons: compounds of carbon, hydrogen, and chlorine atoms (e.g. DDT (C14H9Cl5)).
• Simple carbohydrates: certain types of compounds of carbon, hydrogen, and oxygen (e.g. glucose (C6H12O6)).
Cells: The Fundamental Units of Life
• Cells are the basic structural and functional units of all forms of life.– Prokaryotic cells
(bacteria) lack a distinct nucleus.
– Eukaryotic cells (plants and animals) have a distinct nucleus.
Figure 2-6Figure 2-6
States of Matter
• The atoms, ions, and molecules that make up matter are found in three physical states:– solid, liquid,
gaseous.• A fourth state, plasma,
is a high energy mixture of positively charged ions and negatively charged electrons.– The sun and stars
consist mostly of plasma.