What is Chemistry? tthe study of the composition of matter and the changes it undergoes ccomes from the word alchemy refers to both an early form of the investigation of nature and an early philosophical and spiritual discipline, both combining elements of chemistry, metallurgy, physics, medicine, astrology, semiotics, mysticism, spiritualism, and art all as parts of one greater force ○e○example- making lead into gold aareas of chemistry one can study inorganic- chemicals without carbon organic- chemicals with carbon biochemistry- chemical processes in organisms physical chemistry- transfer of energy, rate… analytical- analyze composition of something

The Scientific Method/Labs  Observe  Hypothesis– If…then…because…  Procedure Controls and Variables ○ manipulating (dependent) variable ○ responding (independent) variable ○ control (s) ○ experimental control  Data Collection quantitative (#’s in tables) qualitative (written observations)  Process the Data– math and graph (which type?)  Conclusion– results supported by data and explanation of those results  Evaluation– identify weaknesses and suggest improvements

Theory vs. Law  theory comprehensive explanation of an important feature of nature that is supported by many facts gathered over time  law does not try to explain, just a concise statement that summarizes the results of many observations and experiments

Dimensional Analysis  figure what you have and where you are going  “cancel out” what you don’t want  Use conversion factors (fraction that equals one)  example: 23,532 seconds = ? hours 23,532 sec. X 1 min. X 1 hour = 1 60 sec. 60 min mm X 1 m = mm  is your answer reasonable? 6.5 hours m