Chemical Formula Guide I need to: Write a formula A metal and a polyatomic ion And I have: So it is Ionic A metal and a nonmetal 2 nonmetals And I will: Write the symbols for the ions of each part. (Roman numerals are + charges) Adjust the quantity of each ion until the charges add up to zero Write the symbol for the metal first Write the number of atoms of that element as a subscript after the symbol Write the symbol for the polyatomic anion last If you need more than one of the polyatomic anion, put parentheses around it and write the subscript outside the parentheses There are NO CHARGES in chemical formulas Example: Calcium nitrate = Ca+2 and NO3-1 I need 1 Ca+2 and 2 NO3-1 to add up to zero Ca(NO3)2 So it is Ionic So it is Covalent And I will: Write the symbols for the ions of both elements. (Roman numerals are + charges) Adjust the quantity of each ion until the charges add up to zero Write the symbol for the metal first Write the number of atoms of that element as a subscript after the symbol Write the symbol for the nonmetal last There are NO CHARGES in chemical formulas Example: Iron (III) oxide = Fe+3 and O-2 I need 2 Fe+2 and 3 O-2 to add up to zero Fe2O3 And I will: Write the symbol for the element in the lowest group first. (exceptions – hydrogen always comes after carbon, and halogens always come before oxygen) Write the number of atoms of that element as a subscript after the symbol. (translate prefixes) Write the symbol for the right-most element last Example: Nitrogen dioxide = NO2

Chemical Formula Guide I need to: Name a compound And I have: 2 nonmetals A metal and a nonmetal A metal and a polyatomic ion So it is Ionic So it is Covalent So it is Ionic And I will: Name the first element first. If there is a subscript after the symbol, use a numeric prefix to name it Name the second element last and change the ending to –ide If there is a subscript after the symbol, use a numeric prefix to name it Example: NO2 is named Nitrogen dioxide Prefixes: 1=mono, 2=di, 3=tri, 4=tetra, 5=penta, 6=hexa, 7=hepta, 8=octa, 9=nona, 10=deca And I will: Name the metal first If it is a transition metal, write its charge as Roman Numerals after the name Name the nonmetal last and change the ending to -ide Example: Fe2O3 is named Iron (III) oxide because the iron atom has a +3 charge THERE ARE NO PREFIXES IN IONIC COMPOUNDS And I will: Name the metal first If it is a transition metal, write its charge as Roman Numerals after the name Name the polyatomic ion last and do not change the name of it Example: Cu(NO3)2 is named Copper (II) nitrate because the copper atom has a +2 charge THERE ARE NO PREFIXES IN IONIC COMPOUNDS