matter: anything that has mass and takes up space (has volume).
solid: definite shape, definite volume, Molecules are rigidly bonded to one another.
liquid: definite volume, but not definite shape. Molecules are continually forming & breaking bonds with one another.
gas: no definite shape or volume. Molecules are not bonded to one another at all.
plasma: molecules are so hot that they cannot hold onto their electrons, so charge is continually changing. Only exists at extremely high temperatures (such as those found on the sun or other stars).
boiling: liquid to gas
condensation: gas to liquid
melting: solid to liquid
freezing: liquid to solid
sublimation: solid to gas
deposition: gas to solid
Any piece of matter has properties (things that are true about it).
physical properties: characteristics of the substance that can be measured or observed without changing the identity of the substance, such as boiling point, freezing point, density, size, shape, color, etc.
chemical properties: characteristics of
the substance having to do with how the atoms and molecules that make up
substance can be combined with or changed into other substances. These
properties can only be measured through changes to the identity of the
substance.
Examples include chemical reactivity and flammability.
physical change: any change that alters the physical properties of the substance, such as freezing, boiling, tearing, crushing, etc.
chemical change: any change that alters the chemical properties of the substance, such as burning, cooking, rusting, decaying, etc.
mixture: two or more different substances sharing the same space or volume. Mixtures can be separated based on differences in physical properties.
Mixtures can be:
homogeneous: every sample of the mixture is the same, no matter where it’s taken from, like with salt water or Gatorade.
heterogeneous: samples of the mixture taken from different locations may be different, like with chocolate chip cookies or orange juice.
pure substance: a pure substance is a substance that cannot be separated or broken down by any physical change. A pure substances can be a:
compound: a substance made out of different kinds of atoms that are chemically bonded together. Compounds can be broken down through chemical changes.
element: a substance made out of only one kind of atom. Elements cannot be broken down through chemical changes. All of the known elements are listed on the periodic table.
Some of the processes used for separating mixtures include:
filtration: separating substances by size—larger ones are trapped on the filter and smaller ones can pass through.
distillation: separating substances that have different boiling points by heating to a temperature where one boils and the other does not.
crystallization: separating substances by letting one freeze but not the other.
chromatography: separating substances by how quickly or slowly they move through another substance.