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Chapter 2. 2.1 and 2.2. Scientific Method. A logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data. Observations. Qualitatitive Descriptive data
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Chapter 2 2.1 and 2.2
Scientific Method • A logical approach to solving problems by observing and collecting data, formulating hypotheses, testing hypotheses, and formulating theories that are supported by data.
Observations • Qualitatitive • Descriptive data • i.e. color, hot or cold, malleability, etc. • Quantitative • Numerical data • i.e. mass, temperature, time, density, etc. Observations of a System: specific part of matter in a given region that has been selected for study
Hypotheses: testable statements • Scientists use their observations/collected data to find relationships or patterns • The hypothesis serves as a basis for making predictions (“if-then” statements) • Example: If plants are watered with a 10% detergent solution, their growth will be negatively affected.
Testing/Experimentation • Use of controls and variables to test the predictions • Based on testing results, predictions are then confirmed, modified or discarded
Modeling • Uses the data collected to explain your results • An explanation of how something occurs and HOW data or events are related • Visual, verbal, or mathematical • A successful model may become part of a theory • THEORY = a broad generalization that explains a body of facts or phenomena
Units of Measurements • Measurements represent quantities (have size, magnitude, amount) • Example: teaspoon represents volume inch represents length • To express measurements, scientists use SI units • Standardized single measurement system • Base Units: 7 base units (yellow paper) • Prefixes = these are added to SI base units to indicate larger or smaller quantities • 1 cm = centi-meter = 10-2 meters = 1/100th meter • Derived Units = combined SI units form derived units • Area = lenthx width = mxm = m2 • Density = mass/volume = g/mL or g/cm3 • Molar mass = mass/amount of substance = g/mol