| A | B |
|---|
| Molecule | a COVALENTLY bonded substance; can be atoms of the same element (Ex: diatomic elements/molecules); molecular substance = covalent substance |
| Compound | a substance composed of two or more atoms from different elements CHEMICALLY bonded together |
| Bond | forces of attraction that hold atoms together in a molecule or compound |
| Octet Rule | atoms bond together in order to have 8 electrons in their valence shell |
| Exothermic | energy is RELEASED as a product of a chemical reaction |
| Endothermic | energy is CONSUMED as a product of a chemical reaction |
| Ionic Bond | chemical bond involving the TRANSFER of electrons between a metal and nonmetal atom (metals lose, nonmetals gain); electronegativity difference between elements typically GREATER than 1.7 |
| Covalent Bond | chemical bond involving the SHARING of electrons between two nonmetal atoms; electronegativity difference between elements typically LESS than 1.7 |
| Oxidation number | the “charge” an element has within a compound |
| Polyatomic ions | atoms of two or more elements chemically bonded together and having a NET CHARGE |
| Stock system | system using Roman numerals (appearing in parentheses) after the element symbol to indicate the oxidation number of a TRANSITION METAL |
| Binary compound | compound containing 2 ELEMENTS (example: CO2) |
| Ternary compound | compound containing 3 ELEMENTS (example: C6H12O6) |
| Polar molecule | a covalent molecule with an unequal sharing of electrons; contains atoms of two different nonmetal elements (all covalent compounds that are NOT diatoms) |
| Nonpolar molecules | a molecule with symmetrical/equal sharing of electrons |
| Intermolecular forces (IMF’s) | weak forces between molecules that hold the molecules to one another; not actually chemical bonds |
