| A | B |
| Matter | Anything that has mass and takes up space |
| Mass | The quantity of matter an object has |
| Elements | Simplest kind of matter; cannot be broken down chemically |
| Atom | Simplest particle of an element |
| Nucleus | The central region of an atom; bulk of atom's mass here |
| Proton | Positively charged subatomic particle in nucleus |
| Atomic Number | Number of protons in an atom |
| Mass Number | Number of protons plus neutrons in an atom |
| Electrons | Negatively charged subatomic particle that orbits the nucleus |
| Orbital | A 3D region around the nucleus where electrons are probably found |
| Isotopes | Atoms of the same element with different number of neutrons |
| Compounds | Made up of 2 or more atoms bonded together |
| Chemical Bonds | attractive forces that hold atoms together |
| Covalent Bonds | When two atoms share one or more pairs of electrons |
| Molecule | simplest part of a substance that retains all properties of that substance |
| Ion | An atom or molecule with a charge |
| Ionic Bond | The transfer of an electron(s) so that two atoms become oppositely charged and attract to each other |
| Energy | The ability to do work |
| Chemical Reaction | One or more substances change to produce one or more different substances |
| Reactants | The substances you begin with in a reaction (left side of equation) |
| Products | The substances you end with in a reaction (right side of equation) |
| Metabolism | All the chemical reactions that occur in an organism |
| Activation Energy | The amount of energy needed to start a reaction |
| Catalysts | Speed up reactions by lowering the activation energy |
| Enzyme | A biological catalyst |
| Redox Reactions | Reactions where there is a transfer of electrons between atoms |
| Oxidation Reaction | When a reactant loses an electron and becomes positive |
| Reduction Reaction | When a reactant gains an electron and becomes negative |
| Polar | A neutral molecule that has an uneven distribution of charges |
| Hydrogen Bond | The force of attraction between a hydrogen atom with another atom or molecule with a full or partial negative charge |
| Cohesion | Attractive force between two of the same molecules |
| Adhesion | Force of attraction between two different types of molecules |
| Capillarity | Attraction between molecules that results in rise of surface of a liquid when in contact with a solid |
| Solution | Mixture in which one or more substances are uniformly distributed in another substance |
| Solute | The substance that gets dissolved in a solvent |
| Solvent | The substance in which the solute gets dissolved in |
| Concentration | The amount of solute in a fixed amount of solvent |
| Saturated Solution | Solution in which no more solute can dissolve |
| Aqueous Solution | Solution in which water is the solvent |
| Hydroxide Ion | OH- more available in bases |
| Hydronium Ion | H3O+ more available in acids |
| Acids | More H3O+ ions, sour, corrosive, low pH |
| Bases | More OH- ions, bitter, slippery, high pH |
| pH Scale | Logarithmic scale comparing relative amounts of OH- and H3O+ ions in solution (from 0 - 14) |
| Buffers | Chemical substances that neutralize small amounts of acids or bases added to a solution |