Question | Answer |
matter | anything that has mass and takes up space, anything that has inertia |
3 classes of matter | elements, compounds, mixtures |
substance | matter in pure form- elements or compounds |
element | substance that cannot be broken down into simpler substances by ordinary means |
atom | smallest particle of an element that has the properties of the element |
compound | a pure substance made up of two or more elements that are chemically combined |
molecule | the smallest part of a covalent compound |
mixture | two or more substances which do not combine (unite) chemically, can be separated by physical means |
four characteristics of mixtures | can be separated by physical means, homogenous or heterogenous, are in a composition which may vary, can consist of two components which vary in properties and composition |
homogenous mixture | a mixture whose makeup is the same throughout; uniform |
heterogenous mixture | a mixture whose makeup differs from point to point; nonuniform |
three classes of mixtures | solutions, suspensions, colloids |
Six techniques used to separate a mixture | dissolving and filtering, evaporation, sifting, distillation, decanting, separating by magnets |
dissolving and filtering | find a solvent for one of the substances but not the other |
evaporation | heat or let stand to allow one substance to vaporize leaving the other behind |
sifting | separate by size through a sieve |
distillation | evaporate one substance from another by heating, then recover the substance by cooling |
decanting | gently pour off a liquid leaving the sediment behind |
separating by magnets | separate ferrous (iron) substances from nonferrous |
What technique is used to separate sand and rocks? | sifting |
What techniques are used to separate sand and water? | distillation, evaporation, filtering, decanting |
What techniques are used to separate sand and salt? | dissolving and filtering, evaporate |
What techniques are used to separate salt and water? | evaporate and distillation |
What technique is used to separate oil and vinegar? | decanting |