02 naming and formula writing
- 1. NAMING & FORMULA WRITING
- 2. Examine the number of valence electrons for each atom: What do you notice? IONS AND THEIR CHARGES
- 3. TREND: -Elements in the same group have the same number of valence electrons -Thus elements in the same group have similar reactivity Examine the number of valence electrons for each atom: Example: All alkali metals have one valence electron IONS AND THEIR CHARGES
- 4. - Elements become stable by achieving 8 valence electrons (except for hydrogen and helium, which achieve 2 electrons) - Noble gases are non-reactive because they have 8 electrons - This is called the Octet Rule The number of valence electrons can determine reactivity: IONS AND THEIR CHARGES
- 5. How many valence electrons does each atom need to gain or lose to achieve a full octet? Alkali metals lose 1 electron Alkali earth metals lose 2 electrons Group 13 elements lose 3 electrons Group 14 elements lose or gain 4 electrons IONS AND THEIR CHARGES
- 6. How many valence electrons does each atom need to gain or lose to achieve a full octet? Group 14 elements lose or gain 4 electrons Group 15 elements gain 3 electrons Group 16 elements gain 2 electrons Halogens gain 1 electron Noble gases already have a full octet IONS AND THEIR CHARGES
- 7. Ion charges based on family/group: +1 +2 +3 +/-4 -3 -2 -1 N/A IONS AND THEIR CHARGES
- 8. BINARY IONIC COMPOUNDS MgCl2 magnesium chlorine ide = magnesium chloride 1) Naming:
- 9. Magnesium oxide Mg O 2 2+ - SIMPLIFY!!! = MgO 2) Writing the chemical formula: BINARY IONIC COMPOUNDS
- 10. PbI4 lead iodide Pb I 41 Check charge on non-metal ion to see if you need to “un-simplify” (IV) = lead (IV) iodide IONIC COMPOUNDS WITH MULTIVALENT METALS 1) Naming:
- 11. Copper (II) chloride Cu Cl 2 1+ - = CuCl2 2) Writing the chemical formula: Copper (II) chloride IONIC COMPOUNDS WITH MULTIVALENT METALS
- 12. Na2SO4 sodium sulfate = sodium sulfate 1) Naming: IONIC COMPOUNDS WITH POLYATOMIC IONS
- 13. Calcium chlorate Ca ClO3 2 1+ - = Ca(ClO3)2 2) Writing the chemical formula: IONIC COMPOUNDS WITH POLYATOMIC IONS ( )
- 14. ACIDS Polyatomic ions have modified names in acids Polyatomic ion name Acid anion name Example sulfate sulfuric H2SO4 sulfuric acid chlorate chloric HClO3 chloric acid carbonate carbonic H2CO3 carbonic acid phosphate phosphoric H3PO4 phosphoric acid ACIDS
- 15. H2SO4(aq) Sulfuric acid OXYACID Most acids have hydrogen HCl(aq) Hydrochloric acid BINARY ACID ACIDS 1) Naming:
- 16. bromic acid BrO3H 1 1+ - = HBrO3(aq) ACIDS 2) Writing the chemical formula:
- 17. mono di tri tetra penta hexa hepta octa nona deca NAMING… • Name both elements (change the ending of the element on the right to “ide” • Put prefixes in front of the element • Eliminate the prefix “mono” if it is attached to the first element (the element on the left) WRITING THE FORMULA… • Write the symbols of the elements • Convert the prefixes to subscripts MOLECULAR COMPOUNDSNON-METAL + NON-METAL Prefixes 1 2 3 4 5 6 7 8 9 10
- 18. mono di tri tetra penta hexa hepta octa nona deca Writing the name: PCl5 MOLECULAR COMPOUNDSNON-METAL + NON-METAL phosphorus chlorine ide chloride 1 RULE #3: Eliminate the prefix “mono” if it is attached to the first element (the element on the left) = phosphorus pentachloride
- 19. Writing the formula: sulfur tetroxide MOLECULAR COMPOUNDSNON-METAL + NON-METAL S O1 4 = SO4 Notice how “tetroxide” is NOT spelt as tetraoxide. The “a” in the prefix is eliminated when its followed by an “o”