3. Chemical Bonding and Compound Naming

4. Ionic Bonding Ions are atoms that have lost or gained one or more electrons, resulting in a positive or negative charge Cation = a positively charged ion Anion = a negatively charged ion

5. Cl O * Are the following ions, cations or anions? Chlorine ion Magnesium ion Oxygen ion * * * * * * * gains 1 electron Cl 1- anion Mg * * loses 2 electrons Mg 2+ cation * * * * * * gains 2 electrons O 2- anion * *

6. Elements in the vertical column families develop the same ionic charges: Metals tend to lose electrons (form cations). Non-metals tend to gain electrons (form anions). Metal cation + Non-metal anion = ionic compound.

7. Naming Binary Ionic Compounds A binary ionic compound is a compound composed of a metal cation and a non-metal anion. The first part of the name identifies the positive ion, which is the metal cation. The second part of the name identifies the negative ion, which is the non-metal anion. The name of the non-metal ion always ends with the suffix –ide. Elements in Ionic Compound Name of Ionic Compound magnesium and phosphorus sodium and chlorine calcium and bromine aluminum and oxygen magnesium phosphide sodium chloride calcium bromide aluminum oxide

8. Writing the chemical formulas for binary ionic compounds 1. Write the symbols with the metal first: aluminum oxide 2. Write the charge above each symbol. 3. Cross over the numbers, not the charges. 4. Never write a subscript 1. 5. Write the formula, reduce if possible.

9. Practice: Elements in Ionic Compound IonsNameChemical Formula potassium and bromineK 1+ and Br 1- potassium bromideKBr magnesium and chlorineMg 2+ and Cl 1- magnesium chlorideMgCl 2 calcium and oxygenCa 2+ and O 2- calcium oxideCaO calcium and iodineCa 2+ and I 1- calcium iodideCaI 2 aluminum and oxygenAl 3+ and O 2- aluminum oxideAl 2 O 3 potassium and chlorineK 1+ and Cl 1- potassium chlorideKCl magnesium and nitrogenMg 2+ and N 3- magnesium nitrideMg 3 N 2 sodium and phosphorusNa 1+ and P 3- sodium phosphideNa 3 P aluminum and sulphurAl 3+ and S 2- aluminum sulphideAl 2 S 3 magnesium and bromineMg 2+ and Br 1- magnesium bromideMgBr 2

10. Now let’s do some serious practice

11. Multivalent Metals Chemical FormulaName SnS 2 Fe 2 O 3 FeF 3 Cr 3 P 2 Multivalent metals have more than one ion charge listed on the periodic table. For example, copper can form ions with a +1 or +2 charge. Cu +1 = copper (I) Cu +2 = copper (Il) Cu 3 N = Practice: tin (IV) sulphide iron (III) oxide iron (III) fluoride chromium (II) phosphide [pronounced “copper one”] [pronounced “copper two”] copper (I) nitride Cu +1 N -3 = nickel (III) sulphide osmium (VIII) carbide Ni 2 S 3 OsC 2

12. Molecular Compounds Molecular compounds are formed when atoms of two or more different elements SHARE electrons A covalent bond is formed when electrons are shared between atoms. for example, water (H 2 0)

13. Diatomic gases H 2, O 2, Br 2, F 2, I 2, N 2, Cl 2 oxygen molecule Elements that have two atoms joined by one or more covalent bonds to form a molecule The anagram is HOBrFINCl

14. ElementFluorineOxygenHydrogen Chemical formula of molecule F2F2 O2O2 H2H2 # of electrons in outer shell 761 # of electrons to complete outer shell 121 # of covalent bonds formed 121 Lewis Diagram of Molecule

15. What is the difference between a molecular formula and structural formula? A molecular formula is a chemical formula – it shows the number of atoms of each element. A structural formula shows the arrangement of the atoms that make up a molecule. water = H 2 O glucose = C 6 H 12 O 6 water = H 2 O glucose = C 6 H 12 O 6 water = H 2 O glucose = C 6 H 12 O 6 water = H 2 O glucose = C 6 H 12 O 6 water = H 2 O glucose = C 6 H 12 O 6

16. Binary molecular compounds Binary molecular compounds are compounds composed of two non-metals joined by one or more covalent bonds. You will be using the roman numeral system to name the compounds. Common examples: carbon dioxide (CO 2 ) carbon monoxide (CO) ammonia (NH 3 )

17. Now let’s do Nomenclature Practice Sheet #2

18. Ionic Compounds with Polyatomic Ions A polyatomic ion is an ion that is composed of more than one type of atom. A ternary compound is a compound composed of three different elements. For example: calcium hydroxide Naming compounds with polyatomic ions follows the same rules as other ionic compounds: 1. Write the cation 1 st (e.g. calcium, Ca +2 ) each molecule is composed of Ca(OH) 2 1 calcium atom, 2 oxygen atoms,and 2 hydrogen atoms. 2. Write the anion 2 nd (e.g. hydroxide, OH - )

19. ChargeNameChemical Formula (CN) - (OH ) - (NO 3 ) - (ClO 3 ) - (HCO 3 ) - (HSO 4 ) - (H 2 PO 4 ) - -2 (CO 3 ) 2- (SO 4 ) 2- (HPO 4 ) 2- -3 (PO 4 ) 3- +1 (NH 4 ) + cyanide hydroxide nitrate chlorate carbonate sulphate phosphate hydrogen carbonate hydrogen sulphate hydrogen phosphate dihydrogen phosphate ammonium

20. NameChemical Formula calcium carbonate (NH 4 ) 2 SO 4 Mg 3 (PO 4 ) 2 potassium sulphate calcium nitrate Fe(HSO 4 ) 3 sodium phosphate LiOH cobalt(II) phosphate Practice: CaCO 3 ammonium sulphate magnesium phosphate K 2 SO 4 Ca(NO 3 ) 2 iron (III) hydrogen sulphate Na 3 PO 4 lithium hydroxide Co 3 (PO 4 ) 2

21. So what are all of these compounds? sodium chloride zinc oxide calcium carbonate calcium hydroxide

22. So what are all of these compounds? nitrogen dioxide dinitrogen tetraoxide carbon tetrachloride sodium nitrite