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Chem Unit 1
laboratory vocab, reactions
| Term | Definition |
|---|---|
| Atom | The smallest unit of matter |
| Element | Multiple atoms of the same kind put togehter |
| Compound | Multiple different atos put together. |
| Heterogeneous | Sand and water in a container (can be separated) |
| Mixtures | Made up of 2 different substances |
| Suspension | A substance that takes a long time to separate (blood) |
| Homogenous | Every atom is the same type/size (Kool-Aid) |
| Methods of separation for heterogenous mixtures | filter, distillation, magnet |
| Methods of separation for homogenous mixtures | a lot of other complex methods |
| Method of separation for heterogenous suspension mixtures | centrifugation |
| Physical change | ex: water+heat>water vapor |
| chemical change | ex: Ka&H202 |
| Accuracy | A measure of how close a measurement comes to the actual value of whatever is measured |
| precision | a measure of how close a series of measurements are to one another |
| percent error | used to determine the accuracy of measurements |
| percent error equation | (|measured-theoretical| / theoretical) * 100 |
| Meniscus | Low point of water's surface tension |
| Purpose of using scientific notation | used to simplify #s that are too big or small to easily work with |
| Alchemists | precursor to the chemist |
| Processes that alchemists developed | separating mixtures, purifying chemicals |
| Lavoisier | father of chemistry who designed a balance that could measure mass to the nearest 0.0005 gram |
| scientific method | observe, hypothesis, experiment, analyze data, accept/reject hypothesis, publish experiment |
| Difference between a theory and a law | Theory=long explanation; changeable. Law= short; equations can come from laws |
| qualitative measurement | smell, touch, sight |
| quantitative measurement | measurements |
| Metric system | M k h da _ d c m |
| Density | Intensive property that depends only on the composition of a substance, not on the size of the sample. |
| Equation for density | mass/volume. ans must have the least sig figs |