CHAPTER 14 Elements of Chemistry

1. CHAPTER 14Elements of Chemistry • Physical & Chemical Properties • Elements to Compounds • Formulas • Naming Compounds

2. Chemistry Physics Biology Earth Science Astronomy

3. What is Chemistry? • Chemistry is the study of substances in terms of • Composition What is it made of? • Structure How is it put together? • Properties What characteristics does it have? • Reactions How does it behave with other substances?

4. Major divisions of Chemistry Elements besides Carbon Methods of analysis Theory and concepts Carbon based compounds Chemistry of living things • General • Inorganic • Analytical • Physical • Organic • Biochemistry

5. What is Chemistry? “The study of Matter and its Changes.” • Matter • The stuff things are made of. • Has Mass and takes up space. • (Air, water, rocks, etc..) • The amount of stuff (in g’s) • (Bowling Ball > Balloon) Weight on earth. Pull of Gravity on matter.

6. Matter Mixture Pure Substance Element Compound Fe + S FeS Fe Mg + O2 MgO Mg Classification of matter

7. What is Chemistry? • “The study of Matter and its Changes.” Physical Changes= Changes in a Physical Property • Appearance: • melting, freezing, evaporation… • stretching, molding, cutting…

8. Physical properties • Characteristics that can be evaluated without changing the composition of the material. • Examples • Color • Odor • Taste • Feel • Shape Density Melting / Freezing point Boiling point Compressibility Form (foil, wire, powder…)

9. Physical properties • A physical property describes the look or feel of a substance.

10. Elemental states at 25oC H He Solid Liquid Li Be B C N O F Ne Gas Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba Ls Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 6 - 2

11. Changes of Phase Fast, far apart, Random Vapor Condense Vaporize Boiling Pt Moderate, close, Random arrangement Liquid Melting Pt = Freezing Pt Melt Freeze Slow, close, Fixed arrangement Solid

12. Changes of Phase Vapor Deposit Frost Liquid Sublime Freeze Dry Solid

13. Physical Changes

14. What is Chemistry? • “The study of Matter and its Changes.” Physical Changes= Changes in a Physical Property • Appearance: • melting, freezing, evaporation… • stretching, molding, cutting… Chemical Changes = Changes in a Chemical Property Chemical Composition:

15. Chemical Properties It is a chemical property of iron to transform into rust.

16. Chemical Changes • Change in the Chemical Composition Examples: Burning of Magnesium Rusting of Iron Decomposing of wood Souring of Milk

17. Chemical Changes

18. Examples Which are chemical or physicalchanges? • Mulching leaves Tarnishing Silver Fermentation Carbonated Beverage going flat Making ice into water Bleaching a stain

19. Physical and Chemical Properties CHECK YOUR NEIGHBOR The transformation of oxygen, O2, into ozone, O3, is an example of • a physical change. • a chemical change. • both a physical and chemical change. • neither a physical nor chemical change. O=O O O O=O O O=O O O O oxygen ozone

20. Physical and Chemical Properties CHECK YOUR ANSWER The transformation of oxygen, O2, into ozone, O3, is an example of • a physical change. • a chemical change. • both a physical and chemical change. • neither a physical nor chemical change. O=O O O O=O O O=O O O O oxygen ozone Explanation: The same kinds of atoms are involved but how they are arranged is completely different. Thus, a new substance has been formed.

21. Determining Physical and Chemical Changes CHECK YOUR NEIGHBOR Melting a piece of solid gold would be… • a physical change. • a chemical change. • both a physical and chemical change. • neither a physical nor chemical change.

22. Determining Physical and Chemical Changes CHECK YOUR ANSWER Melting a piece of solid gold would be… • a physical change. • a chemical change. • both a physical and chemical change. • neither a physical nor chemical change. Explanation: The gold is still gold, it is now in a liquid state.

23. Determining Physical and Chemical Changes CHECK YOUR NEIGHBOR Tarnishing a piece of silver would be… • a physical change. • a chemical change. • both a physical and chemical change. • neither a physical nor chemical change.

24. Determining Physical and Chemical Changes CHECK YOUR ANSWER Tarnishing a piece of silver would be… • a physical change. • a chemical change. • both a physical and chemical change. • neither a physical nor chemical change. Explanation: Tarnish transforms pure silver, Ag, to silver sulfide, Ag2S.

25. Elements to Compounds Element: made of only one kind of atom. The term “element” is used when referring to macroscopic quantities. • Elemental formulas: Show proportion atoms bond. Atom: The fundamental unit of an element. The term “atom” is used when discussing the submicroscopic. Compound Formula O2 Oxygen O3 Ozone S8 Sulfur Gold Au HOFBrINCl

26. Elements to Compounds • Compound: A substance consisting of atoms of different elements. Chemical formula: • Shows the proportion by which elements combine Compound Formula Sodium Chloride NaCl NH3 Ammonia Water H2O CH4 Methane

27. Elements to Compounds • Compounds have properties different from the elements from which they are made. Na + Cl2 NaCl

28. Elements to Compounds H2 + O2 H2O H2O  H2 + O2

29. Chemical Reactions • Shows how the Chemical change occurs. Reactants Products  C3H8 + O2 CO2 + H2O + Energy Mg + O2 MgO + Energy Fe + O2 Fe2O3

30. Naming Compounds Ionic Formulas: Metal + Nonmetal: • Guideline 1 • Start with the element farthest to the left in the periodic table. Example: NaCl • For the element to the right, add the suffix -ide.  chloride Sodium Chlorine Na Cl Sodium chloride

31. Naming Compounds Covalent Formulas: Nonmetals Only Example: CO • Guideline 2 • With different possible combinations of elements, use prefixes to remove ambiguity. Oxygen  oxide Carbon C O Carbon Oxide

32. Naming Compounds • Guideline 1 • Start with the element farthest to the left in the periodic table. • For the element to the right, add the suffix -ide. • Guideline 2 • With different possible combinations of elements, use prefixes to remove ambiguity. Examples: CO carbon monoxide CO2 carbon dioxide

33. Naming Compounds Examples: H2O dihydrogen monoxide “Water” H2O2 dihydrogen dioxide “Hydrogen peroxide” • Guideline 3 • Common names are sometimes used for convenience.

34. Naming Compounds • Guideline 1 • Start with the element farthest to the left in the periodic table. • For the element to the right, add the suffix -ide. • Guideline 2 • With different possible combinations of elements, use prefixes to remove ambiguity. • Guideline 3 • Common names are sometimes used for convenience.

35. Naming Compounds CHECK YOUR NEIGHBOR What is the name of the compound with the formula CBr4? Chrobrofor SeeBer4 Carbon bromide Carbon tetrabromide.

36. Naming Compounds CHECK YOUR ANSWER What is the name of the compound with the formula CBr4? Chrobrofor SeeBer4 Carbon bromide Carbon tetrabromide.

37. Ionic compounds Anions Br1- O2- N3- NaBr Na2O Na3N Na1+ Sodium Bromide Sodium Oxide Sodium Nitride Mg2+ MgBr2 MgO Mg3N2 Cations Magnesium Bromide Magnesium Oxide Magnesium Nitride AlBr3 Al2O3 AlN Al3+ Aluminum Bromide Aluminum Oxide Aluminum Nitride FeBr3 Fe2O3 FeN Fe3+ Iron (III) Bromide Ferric Bromide Iron (III) Oxide Ferric Oxide Iron (III) Nitride Ferric Nitride Cu1+ CuBr Cu2O Cu3N Copper (I) Bromide Cuprous Bromide Copper (I) Oxide Cuprous Oxide Copper (I) Nitride Cuprous Nitride

38. Naming covalent compounds carbon monoxide carbon dioxide dinitrogen pentoxide silicon dioxide iodine trichloride diphophorous pentoxide carbon tetrachloride May modify rules to improve the sound. Example - use monoxide not monooxide.