observingchemical+change

= observing chemical change = ====what is the diffrence between and endothermic or an exothermic reaction well the diffrence is the and endothermic reaction abosobs heat and an exothermic reaction reales heat. and an endothermic reaction aobsorbs heat. An endothermic reaction is any chemical reaction that absorbs heat from its environment.evamples of these reactions are:melting ice cubes ==== > An exothermic reaction is a chemical reaction that is accompanied by the release of heat. In other words, the energy needed for the reaction to occur is less than the total energy released. As a result of this, the extra energy is released, usually in the form of heat.examples are The change in state from a gas to liquid or liquid to solid.
 * melting solid salts
 * evaporating liquid water
 * converting frost to water vapor (melting, boiling, and evaporation in general are endothermic processes)
 * converting frost to water vapor (melting, boiling, and evaporation in general are endothermic processes)




=**precipitate ** = ====this is an example of a precipitate. a precipitate is a soild substance thats formed by a chemical reaction takeing place in a solution. precipitates often form in a double decomposition( challoner 50) whats a double decomposition you might ask your self. a double decomposition is a chemical reaction when to salts in whinch inos are shared. this usualy happends in a solution. ====

=**a movie on chemical change **=

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