| Term | Definition |
| Matter | Anything that has mass and/or takes up space (volume) |
| Element | A substance that cannot be broken down into other substances by chemical reactions |
| Molecule | Any combination of atoms |
| Compound | Two or more different elements combined in a fixed ratio |
| Atom | Smallest unit of matter that retains the properties of an element |
| Atomic Number | Number of protons |
| Mass Number | Number of protons plus neutrons |
| Atomic Weight | 1 mole of a sustance = atomic weight in grams |
| Isotope | Atom with an abnormal number of neutrons |
| Proton | Positively charged subatomic particle |
| Neutron | Subatomic particle with no charge |
| Electron | Negatively charged subatomic particle |
| Valence Electron | Outermost electrons in an atom |
| Covalent Bond | Sharing of electrons (Two non-metals) |
| Ionic Bond | Electrostatic attraction of positive and negative ions (Metal and Non-metal) |
| Valence shell | An atom's outermost electron shell |
| Polar Covalent Bond | Unequal sharing of electrons due to difference in electronegativity |
| Cation | Positively charged ion |
| Anion | Negatively charged ion |
| Hydrogen bond | Hydrogen atom covalently bonded to an electronegative atoms is attracted to another electronegative atom |
| Reactants | Starting materials in a reaction |
| Products | Ending materials in a reaction |
| Cohesion | Two or more molecules of the same substance held together by hydrogen bonds |
| Adhesion | Two or more molecules of different substances held together by hydrogen bonds |
| Surface tension | Measure of how difficult it is to stretch/break the surface of a liquid |
| Specific heat | Amount of heat absorbed to change the temperature by 1 degree C for 1 g of a substance |
| Heat of vaporization | Quantity of heat required to turn liquid to gas |
| Evaporative cooling | As liquid evaporates surface cools since molecules left behind have less kinetic energy |
| Solute | The substance that dissolves |
| Solvent | The dissolving agent in a solution |
| Hydrophobic | Water fearing (will NOT mix with water) |
| Hydrophilic | Water fearing (mixes with water) |
| Temperature | Measure of heat energy as average kinetic energy |
| Insulation | Water is less dense as a solid, freezing creates protective barrier |
| Acid | Substance that increases [H+] |
| Base | Substance that decreases [H+] |
| Buffer | Substance that minimizes changes in [H+] or [OH-] in a solution |
| Structural Isomer | Diiference in the covalent arragnement of atoms |
| Enantiomers | Mirror image isomers (like your left and right hand) |
| Monomer | Building block (repeating units) |
| Polymer | Long molecule consisting of many repeating units linked by covalent bonds |
| Dehydration reaction | Monomers are joined together and a water molecule is lost |
| Enzymes | Special macromolecules that speed up reactions in cells |
| Hydrolysis | Polymers are disassembled and a water molecule is used |
| Carbohydate | Includes both sugars and polymers of sugars |
| Polysaccharides | Polymers with hundreds to thousands of monosaccharides |
| Starch | Sugar storage molecule for plants, made of glucose monomers (Alpha linked) |
| Glycogen | Sugar storage molecule for animals, made of glucose monomers (Alpha linked), extensively branched |
| Cellulose | Major component of plant cell walls, made of glucose monomers (Beta linked), never branched |
| Fat | Made of glycerol and fatty acids |
| Triglyceride | Three fatty acids linked to one glycerol |
| Saturated fat | No double bonds in fatty acid chain, solid at room temperature |
| Unsaturated fat | Double bonds in fatty acid chain, liquid at room temperature |