Term | Definition |
energy | the ability to do work |
chemical reaction | when one or more chemical substances change to produce one or more different substances |
reactants | a substance or molecule that participates in a chemical reaction (shown on the left side of the equation) |
products | a substance that forms in a chemical reaction |
metabolism | all the chemical reactions that occur in an organism |
activation energy | the amount of energy needed to start the reaction |
catalysts | chemical substances that reduce the amount of activation energy that is needed for a reaction to take place |
enzyme | a protein or RNA molecule that speeds up metabolic reactions without being permanently changed or destroyed. |
redox reaction | reaction in which electrons are transferred between atoms |
oxidation reaction | when a reactant loses one or more electrons, thus becoming more positive in charge |
reduction reaction | when a reactant gains one or more electrons, thus becoming more negative in charge |
polar | describes a molecule with opposite charges on opposite ends |
hydrogen bond | the force of attraction between a hydrogen molecule with a partial positive charge and another atom or molecule with a partial or full negative charge |
cohesion | an attraction that holds molecules of a single substance together |
adhesion | the attractive force between two particles of different substances
ex: water molecules and glass molecules |
capillarity | the attraction between molecules that results in the rise of the surface of a liquid when in contact with a solid |
solution | a mixture in which one or more substances are uniformly distributed in another substance |
solute | a substance dissolved in the solvent |
solvent | the substance in which the solute is dissolved |
concentration | the amount of solute dissolved in a fixed amount of the solution |
saturated solution | a solution in which no more solute can dissolve |
aqueous solution | solution in which water is the solvent |
hydroxide ion | the OH- ion |
hydronium ion | the H30+ ion |
acid | any compound that increases the number of hydronium ions when dissolved in water; turns blue litmus paper red and react with bases and some metals to form salts |
base | solution that contains more hydroxide ions that hydronium ions |
pH scale | a scale for comparing the relative concentration of hydronium ions and hydroxide ions in a solution |
Buffers | chemical substances that neutralize small amounts of either an acid or a base added to a solution |