Understanding Ions: Types, Naming, and Electron Configurations**

1. What is an ion? Examples of ions: Na+ Mg2+ Fe3+ Cl- S2- When writing electron configurations or orbital diagrams for ions it’s a little harder because it can look like a different atom. Just subtract the missing electrons or add the extra electrons e- Config. and Orb. Diag. for Ions Li+ (1s2 2s0) NOTE He (1s2)

2. A. Vocabulary • Chemical Bond • attractive force between atoms or ions that binds them together as a unit • bonds form in order to… • decrease potential energy (PE) • increase stability

3. Systematic Naming • There are too many compounds to remember the names of them all. • Compound is made of two or more elements that are bonded together by electrostatic forces. • Name should tell us how many and what type of atoms.

4. Cations • Positive ions. • Formed by losing electrons. • More protons than electrons. • Metals form cations. K+1 Has lost one electron Ca+2 Has lost two electrons

5. Anion • A negative ion. • Has gained electrons. • Non metals can gain electrons. • Charge is written as a super script on the right. F-1 Has gained one electron O-2 Has gained two electrons

6. Compounds • Follow the Law of Definite Proportion. It states that compounds have a constant composition (there are always the same number and types of atoms in the compound).

7. Formula Unit • The smallest whole number ratio of atoms in an ionic compound. • Ions surround each other so you can’t say which is hooked to which.

8. Charges on ions • For most of the Group A elements, the Periodic Table can tell what kind of ion they will form from their location. • Elements in the same group have similar properties. • Including the charge when they are ions.

9. +1 +2 +3 -3 -2 -1

10. Naming ions • We will use the systematic way. • Cation- if the charge is always the same (Group A) just write the name of the metal. • Transition metals can have more than one type of charge. • Indicate the charge on transition metals with roman numerals in parenthesis.

11. Name these • Na+1 sodium ion • Ca+2 calcium ion • Al+3 aluminum ion • Fe+3 iron(lll) ion • Fe+2 iron(ll) ion • Li+1 lithium ion

12. Write Formulas for these • Potassium ion • Magnesium ion • Copper (II) ion • Chromium (VI) ion • Barium ion • Mercury (II) ion

13. Naming Anions • Anions are always the same. • Change the element ending to – ide • F-1 Fluorine

14. Naming Anions • Anions are always the same. • Change the element ending to – ide • F-1 Fluorin

15. Naming Anions • Anions are always the same • Change the element ending to – ide • F-1 Fluori

16. Naming Anions • Anions are always the same • Change the element ending to – ide • F-1 Fluor

17. Naming Anions • Anions are always the same • Change the element ending to – ide • F-1 Fluori

18. Naming Anions • Anions are always the same • Change the element ending to – ide • F-1 Fluorid

19. Naming Anions • Anions are always the same • Change the element ending to – ide • F-1 Fluoride

20. Name these • Cl-1 • N-3 • Br-1 • O-2

21. Write these • sulfide ion • iodide ion • phosphide ion • chloride ion

22. Polyatomic ions • Groups of atoms that stay together and have a charge. • You must memorize these. • Nitrate NO3-1 • Nitrite NO2-1 • Hydroxide OH-1

23. And These: Sulfate SO4-2 Sulfite SO3-2 Carbonate CO3-2 Phosphate PO4-3 Ammonium NH4+1 Polyatomic ions

24. Ions in Ionic Compounds

25. Naming Binary Ionic Compounds • Binary Compounds - 2 elements. • Ionic - a cation and an anion. • To write the names just name the two ions. • Easy with Representative elements. • Group A • NaCl = Na+ Cl- = sodium chloride • MgBr2 = Mg+2 Br- = magnesium bromide

26. Naming Binary Ionic Compounds • The problem comes with the transition metals. • Need to figure out their charges. • The compound must be neutral with the same number of + and – charges. • Use the anion to determine the charge on the positive ion.

27. Naming Binary Ionic Compounds • Write the name of CuO • Need the charge of Cu • O is -2 • copper must be +2 • You write Copper (II) oxide • Name CoCl3 • Cl is -1 and there are three of them = -3 • Co must be +3 Cobalt (III) chloride

28. Naming Binary Ionic Compounds • Write the name of Cu2S. • Since S is -2, the Cu2 must be +2, so each one is +1. • copper (I) sulfide • Fe2O3 • Each O is -2 3 x -2 = -6 • 2 Fe must = +6, so each is +3. • iron (III) oxide

29. Naming Binary Ionic Compounds • Write the names of the following • KCl • Na3N • CrN • Sc3P2 • PbO • PbO2 • Na2Se

30. Writing Formulas • The charges have to add up to zero. • Get charges on pieces. • Cations from name off the table. • Anions from table or polyatomic. • Balance the charges by adding subscripts. • Put polyatomics in parenthesis.

31. Writing Formulas • Write the formula for calcium chloride. • Calcium is Ca+2 • Chloride is Cl-1 • Ca+2 Cl-1 would have a +1 charge. • Need another Cl-1 • Ca Cl2

32. Write the formulas for these • Lithium sulfide • tin (II) oxide • tin (IV) oxide • Magnesium fluoride • Copper (II) sulfate • Iron (III) phosphide • gallium nitrate • Iron (III) sulfide

33. Write the formulas for these • Ammonium chloride • ammonium sulfide • barium nitrate

34. Things to look for • If a cation has (), the roman numeral is its charge. • If anions end in -ide they are probably off the periodic table (Monoatomic) • If anion ends in -ate or -ite it is polyatomic

35. Molecular Compounds Writing names and Formulas

36. Two Types of Compounds • Molecular compounds • Made of molecules. • Made by joining nonmetal atoms together into molecules.

37. Two Types of Compounds • Ionic Compounds • Made of cations (metals) and anions (nonmetals). • The electrons lost by the cation are gained by the anion. • The cation and anions surround each other. • Smallest piece is a FORMULA UNIT.

38. Two Types of Compounds Ionic Molecular Smallest piece Formula Unit Molecule Types of elements Metal and Nonmetal Nonmetals Solid, liquid or gas State solid Melting Point High >300ºC Low <300ºC

39. Chemical Formulas • Shows the kind and number of atoms in the smallest piece of a substance. • Molecular formula- number and kinds of atoms in a molecule. • CO2 • C6H12O6

40. Molecular compounds • made of just nonmetals • smallest piece is a molecule • can’t be held together because of opposite charges. • can’t use charges to figure out how many of each atom

41. Easier • Ionic compounds use charges to determine how many of each. • Have to figure out charges. • Have to figure out numbers. • Molecular compound’s name tells you the number of atoms. • Uses prefixes to tell you the number

42. Prefixes • 1 mono- • 2 di- • 3 tri- • 4 tetra- • 5 penta- • 6 hexa- • 7 hepta- • 8 octa-

43. Prefixes • 9 nona- • 10 deca- • To write the name write two words

44. Prefixes • 9 nona- • 10 deca- • To write the name write two words Prefix name Prefix name -ide

45. Prefixes • 9 nona- • 10 deca- • To write the name write two words • One exception is we don’t write mono- if there is only one of the first element. Prefix name Prefix name -ide

46. Prefixes • 9 nona- • 10 deca- • To write the name write two words • One exception is we don’t write mono- if there is only one of the first element. • No double vowels when writing names (oa oo) Prefix name Prefix name -ide

47. N2O dinitrogen monoxide NO2 nitrogen dioxide Cl2O7 Dichlorine Heptaoxdide CBr4 Carbon tetrabromide CO2 Carbon dioxide BaCl2 Barium dichloride Name These

48. Write formulas for these • diphosphorus pentoxide • tetraiodide nonoxide • sulfur hexaflouride • nitrogen trioxide • Carbon tetrahydride • phosphorus trifluoride • aluminum chloride

49. Acids Writing names and Formulas

50. Acids • Compounds that give off hydrogen ions when dissolved in water. • Must have H in them. • will always be some H next to an anion. • The anion determines the name.