1. Bonding, Compounds, Reactions

2. Periodic Table Review

3. What does the periodic table tell me? Element symbol Atomic number: number of protons (and usually electrons, neutrons) Atomic mass: the average of all the isotopes’ mass What type of element it is (metal, nonmetal, etc) What elements can bond together (valence #) In what ratio elements bond (oxidation #)

4. Reading the Periodic Table: Elements S 16 32.06 Element symbol Atomic mass Atomic number

5. Types of Elements Metals: usually shiny, conductors, malleable, ductile, solids at room temperature. On left side of periodic table Non-metals: gas or brittle solid at room temperature, insulators. On right side of periodic table. Metalloids: have properties of both metals and non-metals. Between metals and non-metals.

6. Three types of Elements

7. Things to remember with symbols They are either one or two letters. Only the first letter is capitalized! Some symbols are based on the Latin name Some of the newest symbols use three letters until they are renamed (the atomic number in Latin)

8. Periodic Table Noble GasNon- metals Metalloids Metals Transition Metals Halogen

9. Types of Elements Noble Gas: Chemically stable. Has outer valence level full. “Happy” AKA: Inert elements. Don’t bond with others. Halogens: Are non-metals. Bond VERY easily. Have 7 electrons in outer shell. Non-metals: Do not easily conduct electricity or heat. Metalloids: Have traits of both metals and non-metals. Metals: Good conductor of heat and electricity, shiny, ductile (pulled into a wire), and malleable (pounded into flat sheets) Transition metals: Metals that can have two different valence numbers. Is shown in the formula. Example: Fe (II)

10. Periodic Table Alkali metals Alkaline Earth metals Transition metals

11. Chemical Bonds The forces that hold atoms or ions together

12. Word wizard: Ionic Bond Ionic Bond Your definitionImportant Points Examples Non-Examples Bond that is formed by the “stealing” of electrons. One atom is now + and one is now -. This makes them attract to each other. Most are solid at room temp. Sodium Chloride: NaCl Sugar: C 6 H 12 O 6 Water: H 2 O Diatomic molecules: Cl 2, H 2, N 2 (gasses)

13. Word wizard: Covalent Bond Covalent Bond Your definitionImportant Points Examples Non-Examples Sodium Chloride: NaCl Sugar: C 6 H 12 O 6 Water: H 2 O Diatomic molecules: Cl 2, H 2, N 2 (gasses) Bond that is formed by the “sharing” of electrons. A stronger bond than ionic. Atoms can share more than one electron. Most are liquid or gas at room temp.

14. Word wizard: Anion anion Your definitionImportant Points Examples Non-Examples Chlorine Oxygen Nitrogen Non-metals An ion that has a negative charge; has extra electrons. Anions have more electrons than protons. This makes them negative overall. Sodium Potassium Magnesium Metals

15. Word wizard: Cation Cation Your definitionImportant Points Examples Non-Examples An ion that is positively charged; has less electrons Cations lose electrons. They have more protons than electrons and are positively charged. Sodium Potassium Magnesium Metals Chlorine Oxygen Nitrogen Non-metals

16. Word wizard: Chemical Formula Chemical formula Your definitionImportant Points Examples Non-Examples A shorthand way of writing compounds using their symbols. Large and small letters. Shows what elements are in a compound and how many of each. H 2 O C 6 H 12 O 6 NaCl Water Sugar Salt

17. Word wizard: Chemically Stable Chemically Stable Your defintionImportant Points Examples Non-Examples Elements that have the outer electron shell full. Also called “Noble Gases” or “Inert Elements” Will not typically bond with other elements. Likes to be ALONE! Helium Krypton Neon Xenon Argon Radon Gold Carbon Sodium Nickel Potassium Oxygen

18. Valence Numbers 12354867 Valence

19. Diatomic Molecules Covalent bond between identical atoms. Usually a gas Examples: –H 2 (hydrogen gas) –O 2 (oxygen gas) –N 2 (nitrogen gas) Nitrogen has 5 electrons in the outer shell. It wants 8. Two nitrogen atoms share three electrons. BONDED!

20. Making Compounds Let’s bond, shall we?

21. Valence Numbers Valence electrons: how many electrons are in the outer shell. Chemically stable: elements having their outer shell full. The noble gases are chemically stable without bonding. To fill the outer shell, elements can share or steal electrons (bond). To be “Happy” atoms typically want 8 electrons in the outer shell (ionic or covalent bonds)

22. Ionic bonding Stealing electrons This makes one negatively charged (it has an extra electron that it stole). The other is now positively charged (had an electron taken). Opposites attract! Ionic bonds are weaker than covalent. Compounds that are solids at room temperature are usually from ionic bonds.

23. Covalent Bonding From sharing electrons Covalent bonds are stronger than ionic Compounds that are liquids or gas at room temperature are typically covalent bonds. Diatomic: Some elements will covalently bond with themselves!

24. Common Household Compounds Salt: Water: Carbon Dioxide: Carbon Monoxide: Stomach Acid: Ammonia: Bleach: Sand: Baking Soda: Propane: Vinegar: NaCl H2OH2O CO 2 CO HCl NH 4 NaClO SiO 2 NaHC0 3 C3H8C3H8 HCH 3 O 2

25. Ionic Compound Naming Metal first then nonmetal Nonmetal gets –ide ending

26. Dihydrogen Monoxide The dangers, uses and potential threats posed by this chemical, Dihydrogen Monoxide, are widespread, and some feel, terrifying. Here is just a small taste of what Dihydrogen Monoxide (DHMO) is:  Some call Dihydrogen Monoxide the "Invisible Killer"  In it’s gaseous form, DHMO can cause severe burns  Dihydrogen Monoxide is found in all cancerous tumors  Athletes use DIHYDROGEN MONOXIDE, or DHMO, to enhance performance  Dihydrogen Monoxide has been found to cause failure in automotive breaks  Dihydrogen Monoxide is a major component of acid rain  Thousands die each year after inhaling dihydrogen monoxide  Dihydrogen Monoxide can be deadly Visit DHMO.org to find out moreDHMO.org

27. What’s in a name? Mono = one Di = two Tri = three Tetra = four Penta = five Examples: –Carbon Monoxide CO –Carbon Dioxide CO 2 –Dihydrogen Monoxide ?? H2OH2O

28. Covalent Compound Naming If only one atom in first element the name does not get a prefix The element farther to the right on the periodic table is named second and ends in -ide

29. Dot Diagrams What you need to know to make a dot diagram: Chemical symbol valence number How to draw the dot diagram of an element: 1. Write the symbol 2. Find the valence number 3. Fill in dots –two together (the S ones) –one in other sides until you run out of room. P

30. More Dot Diagrams Li F Mg Se Kr Ge

31. I’m still seeing dots! Sr As Why is this one right? He Because Helium only has two electrons in the first place!

32. Oxidation numbers -2 -3 +/-4+3 +2 +1

33. Making Compounds Criss-Cross Method: –List the Metal first, non-metal second. –Write the oxidation number above the symbol. –Criss-cross the numbers. (a 1 does not need to be written, drop the + or -) –Final answer lists only the subscripts (numbers below the line) –If they are the same number, they cancel out Example: Combine Hydrogen and Chlorine Cl +1 = HCl H

34. Now try these... HO +1-2 Hydrogen and Oxygen H 2 O Magnesium and Nitrogen MgN +2 -3 Mg 3 N 2

35. Writing Equations Remember the “criss cross” method. –Use the oxidation number –Don’t write in 1’s or the charges –Oxidation numbers of transition elements are given in a roman numeral. –Put in “lowest terms” HO +1-2 H 2 O Example: Combine H and O Example: Combine Fe (III) and O Fe O -2+3 Fe 2 O 3

36. Writing Equations: something new Monoatomic Ions: –“normal” –one element –can get from the periodic table or roman numerals –what you’ve been working with –Example: H 2 0 Polyatomic Ions: –compounds that always work together. –Always has more than one element –Get the information off a chart –Criss cross method still works. –Keep these elements together! Example: Combine Potassium and Permanganate K MnO 4 +1 KMnO 4

37. More Practice: Polyatomic Ions Combine: Iron (II) and Nitrate FeNO 3 +2 Fe(NO 3 ) 2 Combine: Calcium and Carbonate CaCO 3 +2 -2 CaCO 3

38. Word wizard Your definition Important Points Real example Analogy/memory hook Alloy Not ALL metals are mixtures. (All = alloy) Alloys are like allies (mixed but not the same) Two or more metals melted down and mixed together. Sterling silver, 14 karat gold, bronze, brass The mixture can have new properties. (lower melt point, stronger, etc.

39. Word wizard Your definition Basic equation Real example Analogy/memory hook Synthesis Reaction Reaction where substances are combined to make a new substance. Like two people going out and becoming a “couple”. Dating is a “sin” 2Mg + O 2 2MgO A + B AB

40. Word wizard Your definition Basic equation Real example Analogy/memory hook Single replacement Reaction One ingredient “kicks out” the other. Leaders always stay leaders! Getting “dumped” for someone else. One ends up single A + BC AC + B D + BC BD + C Li + FeBr 2 LiBr + Fe

41. Word wizard Your definition Basic equation Real example Analogy/memory hook Double replacement Reaction Elements will change partners in this type of reaction. Leaders are always leaders! Switching dates at the prom. Nobody gets left alone! AB + CD AD + CB AgNO 3 + NaCl AgCl + NaNO 3

42. Word wizard Your definition Basic equation Real example Analogy/memory hook Decomposition Reaction A substance is broken down into its “parts” in this reaction A couple breaking up. Things “break down” when they decompose. AB A + B 2H 2 O H 2 + O 2 elec

43. Word wizard Your definition Basic equation Real example Analogy/memory hook Combustion Reaction A reaction where two of the products are water and carbon dioxide Combustion = fire Picture a fire with smoke (CO 2 ) and water(H 2 0) to put it out. A + B CO 2 + H 2 0 HCl + Na 2 CO 3 CO 2 + NaCl + H 2 O

44. Word wizard Your definition Important Points Real example Analogy/memory hook Endothermic Reaction Chemical reaction where heat is ABSORBED. Heat being absorbed makes it feel COLD. Break and shake ice pack. (Heat is absorbed by ice pack, but it feels cold) Endo has a “d” in it. Cold has a “d” in it. Endothermic reactions FEEL cold.

45. Word wizard Your definition Important Points Real example Analogy/memory hook Exothermic Reaction Chemical reaction where heat is released. This reaction will feel warm/hot. “Hand warmers” BenGay, Thermocare hot wraps “Exo” = “exit” Heats EXITS an exothermic reaction. (it feels warm)

46. You can’t play “God” Law of Conservation of Mass says that we can’t create or destroy mass! Example: the weight of a piece of paper will be the same as the weight of the ash, smoke, etc after you burn it!! In chemical reactions, you need to have the same amount of atoms before and after the reaction!

47. It’s a balancing act Ag + H 2 S Ag 2 S + H 2 Ag H S H S 1 2 1 2 2 1 Not Balanced! Conservation of mass says we can’t create or destroy anything!!

48. It’s a balancing act Ag + H 2 S Ag 2 S + H 2 Ag H S H S 1 2 1 2 2 1 2 2