Ionic Naming & Formula Writing Covalent Naming & Formula Writing Ionic Naming: Covalent Naming: Formula will always start with a metal (cation) Formula given will start with a nonmetal (anion), Formula will sometimes have a polyatomic ion followed by a nonmetal (look at your reference sheet) o Right hand side above the staircase Always name the metal first You need prefixes for the amount of atoms you o Parent name on the periodic table have of each element o If it’s a transition metal, you will have to First nonmetal: figure out the charge (these are the o Parent atom on the periodic table metals in the middle of the periodic table. o Never start with “mono” prefix if there is o Transition metals ALWAYS NEED A only one atom CHARGE in parentheses between the o If more than one atom of first nonmetal, cation and anion. give prefix o Base the charge on the anion’s charge and Second nonmetal: quantity. o Prefix + parent atom root, and suffix –ide Name the non-metal/polyatomic ion next o Second nonmetal ALWAYS gets a prefix, o Non-metal (anion): -ide suffix even if there is only one atom o Polyatomic ion: name on sheet NO POLYATOMIC IONS Formula name will always be: You will also need to memorize the diatomic o Metal + non-metal/polyatomic ion molecules on the periodic table (there are 7 total) IGNORE THE SUBSCRIPTS FOR NAMING o N, O, F, Cl, Br, I, H Name will always be only TWO WORDS o They are written with a subscript of 2 Example : ALWAYS when naming o Fe 2O3 Example: o First element: iron (transition metal) o SO 2 Need charge: Based on oxygen’s o S = sulfur (nonmetal), only one atom, no charge (-2) prefix needed o Second element: oxygen ; change to o O2 = dioxide , there is a subscript of 2, oxIDE need prefix for oxygen. o Name: Iron (II) oxide o Name: Sulfur dioxide Ionic Formula Writing: Covalent Formula Writing: First name given will be a metal (from left hand Name given will have prefixes (always on side of periodic table all the way over to under the second nonmetal) and will start with a nonmetal staircase on the right hand side) name o Periodic metal (parent name) Both elements will be NONMETALS o Transition metal (will have a CHARGE in Use prefix chart to figure out the quantity of atoms parenthesis between cation/anion) in the formula Second name will be a non-metal (right hand Prefixes become SUBSCRIPTS for atom named. side of the periodic table, above the staircase) or o Example : nitrogen dioxide polyatomic ion name. o Nitrogen = no prefix, so just one atom o Generally: o Di = two o –ide: non-metal o Oxide = oxygen o –ate or –ite polyatomic o Translation : 1 nitrogen atom and 2 o Huge exception : OH or hydroxide. This is oxygen atoms a polyatomic, not H or hydride o Written : NO 2 Write your symbols, then get their charges. CRISS CROSS FOR FORMULA o If charges are exact opposites (i.e. +2 and -2) they cancel; no need for crisscrossing. Charges become subscripts for opposite atom, unless they cancel out Example : o Magnesium oxide o Magnesium: Mg ( +2 ) o Oxide: O (oxygen) ( -2) o Charges cancel , so no crisscross needed o Formula: MgO .