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.

Inference 1.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 2-5

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 (CH 4 ) is the only exception. –All other compounds are inorganic.

Organic Compounds: Carbon Rules Hydrocarbons: compounds of carbon and hydrogen atoms (e.g. methane (CH 4 )). Chlorinated hydrocarbons: compounds of carbon, hydrogen, and chlorine atoms (e.g. DDT (C 14 H 9 C l5 )). Simple carbohydrates: certain types of compounds of carbon, hydrogen, and oxygen (e.g. glucose (C 6 H 12 O 6 )).

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 2-6

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.