click below
click below
Normal Size Small Size show me how
Chemical reactions
Term | Definition |
---|---|
Activation Energy | What is needed to start a chemical reaction |
Arrow | you read the arrow says "yields" in a chemical equation or formula |
Characteristics of a chemical reaction | changes in energy or changes in properties |
Chemical Changes | alter the chemical properties of matter; new substances with new properties are formed |
Chemical Equations | a shorter, easier way to show chemical reactions by using symbols instead of words |
Coefficient | a number placed in front of a chemical formula in an equation. Tells how many atoms or molecules of each reactant and product take part in the reaction |
Conservation of mass | the amount of matter involved in a chemical reaction does not change. the total mass of the reactants must equal the total mass of the products |
Decomposition Reaction | a compound breaks down into simpler substances |
Exothermic | an observable change in energy that shows a chemical reaction took place; a reaction that releases heat; gives off energy, makes it feel warmer; most chemical reactions are this type |
Endothermic | an observable change in energy that shows a chemical reaction took place; a reaction that takes heat from the solution, absorbs energy, makes it feel cooler |
Physical changes | Alter only the physical properties of matter; no new substances are forms |
Precipitate | a solid that forms from solution during a chemical reaction; observable change that shows a chemical reaction took place. |
products | the materials you have after a chemical reaction; written on the right side |
reactants | the materials you have at the beginning of a chemical reaction; written on the left side |
Replacement Reaction | one part of a compound is displaced by an element or compound from another substance. |
States of matter | solid, liquid,gas |
Subscripts | show the number of atoms of an element in a molecule or the ratio of elements in a compound |
Synthesis Reaction | two substances combine to form a new compound. |
Concentration | amount of material in a given amount of another material |
catalyst | materials that increases the rate of reaction |