N AMING C OVALENT C OMPOUNDS

W RITING C OVALENT C OMPOUNDS Made of two anions (2 nonmetals or 1 nonmetal & 1 polyatomic ion) Identify the less electronegative element 1 st (trend = less EN is the one farthest left & farthest down on Periodic Table) The 1 st nonmetal is just given the name as found on the Periodic Table (just like ionic) The 2 nd nonmetal ending is changed to –ide (just like ionic…don’t change polyatomics) Difference = numerical prefixes are used to express how many of each nonmetal are present

W RITING C OVALENT C OMPOUNDS ( CONT.) You never use “criss-cross” method The only time you do not use a prefix is when there is only one of the first nonmetal. NumberPrefix 1Mono 2Di 3Tri 4Tetra 5Penta 6Hexa 7Hepta 8Octa 9Nona 10Deca

C OVALENT C OMPOUND P RACTICE SO 2 N2ON2O NO 2 CCl 4 Cl 2 O 7 PCl 3 SF 6 Si 3 N 4 N(BrO 3 ) 5 H2OH2O Sulfur Dioxide Dinitrogen Monoxide Nitrogen Dioxide Carbon Tetrachloride Dichlorine Heptaoxide Phosphorus Trichloride Sulfur Hexafluoride Trisilicon Tetranitride Nitrogen Pentabromate Water - can use common name

C OVALENT C OMPOUND P RACTICE Phosphorus Trioxide Dinitrogen Pentacarbide Tellurium Noniodide Carbon Monoxide Selenium Heptafluoride Tetraphosphorous Decoxide Arsenic Hexabromide Silicon Dichloride PO 3 N2C5N2C5 TeI 9 CO SeF 7 P 4 O 10 AsBr 6 SiCl 2