Chapter 1

Scientific Method framework for gaining and organizing information many different versions, depends on nature of investigation/problem steps often repeated observations & performing experiments

theory vs. law theory - (aka model) - possible explanation/ interpretation for why nature behaves in a particular way Law - (natural law) - observed or measurable behavior; summary

Measurement every measurement must have a number and a unit mass - measure of the amount of matter grams (g), kilograms (kg) volume - how much space an object takes up liter (L), milliliter (mL) length - distance between 2 points meter (m), cm, mm, km *** know your metric perfixes

Uncertainty in Measurement significant figures - (sig figs) nonzero numbers (1-9)multiply/divide - lowest # sig figs trapped or captured zerosadd/subtract - least # decimal trailing zeros if a decimal places accuracy - agreement with true/accepted value precision - agreement between multiple measurements

Dimensional Analysis aka conversions/factor label method identify your given (know) and what need to find (unknown) be sure units that need to cancel are diagonal multiply the top; divide by the bottom

Temperature & Density Celsius ( C); Fahrenheit ( F); Kelvin (K) conversions: T K = T C T F = T C * (9/5) + 32 T C = (T F - 32) * (5/9) Density = Mass / Volume (D=m/V)

Classification of Matter anything that has mass and takes up space Three main states: solid, liquid, gas Pure Substances: elements & compounds Mixtures: heterogeneous & homogeneous

Lab techniques ways to separate a mixture: chromatography - 2 phases - mobile & stationary paper chromatography distillation - based on readily substance turns to gas filtration - solid and liquids

Phyiscal vs Chemical Physical Properties describe material Physical Changes change in state/form/ property Chemical Properties warnings/ advisaries Chemical Changes completely new substance