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37 Cards in this Set
- Front
- Back
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pure substance
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cannot be separated into simpler substances by physical processes, can also be compounds in definite proportions--can be broken down into individual elements by chemical means
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mixtures
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composed of 2+ pure substances and can be separated by physical processes
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examples of pure substances
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hydrogen
pure water elements |
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examples of mixtures
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muddy water
salt water salad dressing |
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homogeneous mixture
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constituents are distributed uniformly throughout the sample
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examples of homogeneous mixtures
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salt water
brass (metal alloy) |
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heterogeneous mixture
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individual components can be seen as separate substances
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examples of heterogeneous mixtures
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chocolate chip cookies
concrete |
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ways to separate a mixture
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filtration
distillation |
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filtration
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separate a solid from a liquid by passing through a filter ex. practical (sifting) and lab (through funnel or some otha ****)
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distillation
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separate a liquid from mixture by evaporation and recondensation (apparatus or solar still)
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properties of matter
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intensive and extensive
physical and chemical |
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intensive property
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independent of the amount of substance present ex. color, hardness, density
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extensive property
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varies with the quantity of the substance present ex. volume, mass, etc.
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physical properties
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characteristics of a substance that can be observed without it changing into another substance
ex. luster, color, hardness, etc. |
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chemical properties
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characteristic of a material involving its chemical change ex. carbonates produce a gas when added to acidic solutions, burning wood
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states of matter
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solid - definite volume and shape
liquid - definite volume, no shape gas - no shape or volume |
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change state by...
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adding or removing heat
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solid -> liquid
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melting
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liquid -> solid
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freezing
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liquid -> gas
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vaporization
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gas -> liquid
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condensation
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gas -> solid
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deposition
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solid -> gas
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sublimation
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scientific method
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method to acquire knowledge through observation and experimentation
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hypothesis
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tentative and testable explanation for an observation or series of observations
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scientific theory
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general explanation of widely observed phenomena that have been extensively used
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experimental method
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1) observe
2) propose hypothesis 3) test hypothesis 4) refine hypothesis 5) test validity with more trials 6) establish theory but continue to test validity |
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measurement
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comparison of a physical quantity to be measured with a unit of measurement (with a fixed standard of measurement)
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sig figs
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nonzero always significant
leading zeros never significant 0.028937987 trailing zeros are not significant unless after decimal captured zeros always significant |
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exact number
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counted number or defined number. infinite number of sig figs (number of kids in class)
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sig figs multiplication/division
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least precise number is used
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sig figs addition/subtraction
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least number of decimal places
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accuracy
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closeness of a single measurement to its true value
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precision
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closeness of the set of values obtained from repeated measurement of the same quantity
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density
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mass/volume
intensive property |
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temperature scales
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k=c+273.15
c=5/9(f-32) 0 K is absolute zero = lowest temp possible |
