click below
click below
Normal Size Small Size show me how
BHS phy sci unit 8
Vocabulary for Chapters 14 & 15
Term | Definition |
---|---|
activation energy | Energy needed to start a chemical reaction. |
alloy | Mixture of a metal with one or more other elements. |
catalyst | Substance that increases the rate of a chemical reaction but is not changed or used up in the reaction. |
chemical bond | Force of attraction between atoms or ions that occurs when atoms share or transfer valence electrons. |
chemical equation | Symbolic representation of a chemical reaction. |
chemical formula | Symbol of a chemical compound using element symbols and subscripts that shows the ratio of atoms in the compound. |
chemical reaction | Process in which some substances, called reactants, change chemically into different substances, called products |
combustion reaction | Chemical reaction in which a substance reacts quickly with oxygen, producing carbon dioxide, water, and energy; commonly called burning. |
concentration | Number of particles of a substance in a given volume. |
covalent bond | Force of attraction that holds together two atoms that share a pair of electrons. |
covalent compound | Compound forms when atoms of nonmetals form molecules that are held together by covalent bonds. |
decomposition reaction | Chemical reaction in which one reactant breaks down into two or more products. |
endothermic reaction | Chemical reaction that needs a constant input of energy to continue because it takes more energy to break bonds in the reactants than is released when new bonds form in the products. |
equilibrium | Balance between opposing changes, such as the forward and reverse directions of a chemical reaction. |
exothermic reaction | Chemical reaction that releases energy because it takes less energy to break bonds in the reactants than is released when new bonds form in the product. |
hydrogen bond | Weak bond that forms between a slightly positive hydrogen atom in one molecule and a slightly negative atom in another molecule. |
ionic bond | Force of attraction that holds together positive and negative ions that forms when atoms of a metal give up valence electrons to atoms of a nonmetal. |
ionic compound | Compound that forms when oppositely charged metal and nonmetal ions are held together in a crystal by ionic bonds. |
law of conservation of energy | Law stating that energy cannot be created or destroyed in chemical reactions. |
metallic bond | Force of attraction between a positive metal ion and valence electrons it shares with other ions of the metal. |
nonpolar | Not having oppositely charged ends, as in nonpolar covalent bond or nonpolar covalent compound. |
polar | Having oppositely charged ends, as in polar covalent bond or polar covalent compound. |
product | Substance that is produced in a chemical reaction. |
reactant | substance that starts a chemical reaction |
reaction rate | speed at which a chemical reaction occurs |
replacement reaction | chemical reaction in which ions switch places in one compound (single replacement) or in two compounds (double replacement) |
synthesis reaction | Chemical reaction in which two or more reactants combine to form a single product. |