| A | B |
|---|
| Law of Conservation of Mass | No detectable change in the total mass occurs during a chemical reaction |
| Formula mass | The sum of the atomic masses given in a formula of the substance |
| Law of Definite Proportions | Different samples of a pure compound always contain the same elements in the same proportion by mass |
| Limiting Reactant | Element used completely in a reaction |
| Excess Reactant | Element only partially used up in a reaction |
| Octet Rule | In forming compounds, atoms tend to lose, gain or share valence electrons to achieve electron configurations of the noble gases. |
| Ionic Compounds | Formed by the electron transfer process |
| Lewis Symbol | Element's symbol is used to represent the nucleus and the valence electrons are represented by dots arranged around the symbol. |
| Cations | Positive ions that metals form |
| Anions | Negative ions that nonmetals form |
| Ionic Bond | A bond between a cation and an anion |
| Stock System | Roman numerals used directly after the metal's name to give the value of the metal's ionic charge. |
| Covalent Compounds | Sharing of electrons |
| Covalent bond | Type of bond generally associated with the sharing of electrons between two nonmetals |
| Polar Covalent Bond | A bond with a slightly positive end and a slightly negative end |
| Electronegativity | A measure of the ability of an atom in a molecule to draw bonding electrons to itself. |
| Polar Molecule | Experiences a DIPOLE moment |
