1. PowerPoint ® Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings PART A 2 Basic Chemistry

2. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chp. 2 Vocabulary 1.Enzyme 2.Cholesterol 3.Glucose 4.Organic Compound 5.Inorganic Compound 6.Decomposition 7.Electron 8.Atomic # 9.Atomic Mass 10.Valence Shell 11.Elements 12.Atoms 13.Atomic Symbol 14.Proton 15.Neutron 16. Molecule 17. Compound 18. Ionic Bond 19. Covalent Bond 20. Hydrogen Bond 21. SynthesisReaction 22. Matter 23. Energy 24. Kinetic Energy 25. Potential Energy

3. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Matter and Energy  Matter—anything that occupies space and has mass (weight)‏  Energy—the ability to do work  Chemical  Electrical  Mechanical  Radiant

4. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Energy  Stored in the bonds of chemical substances  Broken bonds release (potential) energy and it becomes kinetic energy  Ex: gasoline molecules power you vehicle  Ex: Chemical energy from foods we eat power our body

5. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Electrical Energy  Results from movement of charged particles  Ex: electricity is from electrons flowing across wiring  Ex: Nervous system uses eletrical currents called nerve impulses to transmit messages throughout the body.

6. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Mechanical Energy  Energy directly involved in moving matter  Ex: riding a bike; your legs provide the mechanical energy that moves the pedals  Ex: muscles in you legs shorten, they pull on your bones, causing your limbs to move (allowing you to pedal the bike)‏

7. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Radiant Energy  Travels in waves  Ex: x-rays, infrared radiation, visible light, radio, ultraviolet waves, Sonar

8. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Composition of Matter  Elements—fundamental units of matter  96% of the body is made from four elements  Carbon (C)  Oxygen (O)‏  Hydrogen (H)‏  Nitrogen (N)‏  Atoms—building blocks of elements  Hydrogen – simplest atom

9. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Elements  Unique substances that cannot be broken down into smaller substances by ordinary methods  112 elements are know with certainty; 113-118 are alleged  92 of these elements occur naturally

10. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Atoms  Building blocks of elements  Comes from Greek word meaning “incapable of being divided”  3 subatomic particles  Protons – positive charge;  Neutrons – uncharged (Protons & electrons are heavy particles and have about the same mass)‏  Electrons – negative charge; (equal to the positive charge of protons)‏

11. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Atomic Structure  Nucleus  Protons (p + )‏  Neutrons (n 0 )‏  Outside of nucleus  Electrons (e - )‏ Figure 2.1

12. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Identifying Elements  Atomic number—equal to the number of protons that the atom contains  Protons = # of electrons  Ex: An atom has 5 neutrons, 4 protons, and 4 electrons. Whats the atomic #.  Atomic mass number—sum of the protons and neutrons  Ex: An atom has 5 neutrons, 4 protons, and 4 electrons. Whats the atomic mass #.

13. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Planetary Model vs. Orbital model

14. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Atomic Structure of Smallest Atoms Figure 2.2

15. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Isotopes and Atomic Weight  Isotopes  Have the same number of protons  Vary in number of neutrons Figure 2.3

16. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Isotopes and Atomic Weight  Atomic weight  Close to mass number of most abundant isotope  Atomic weight reflects natural isotope variation

17. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Radioactivity  Radioisotope  Heavy isotope  Tends to be unstable  Decomposes to more stable isotope  Radioactivity—process of spontaneous atomic decay

18. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Molecules and Compounds  Molecule—two or more like atoms combined chemically  Compound—two or more different atoms combined chemically Figure 2.4

19. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Reactions  Atoms are united by chemical bonds  Atoms dissociate from other atoms when chemical bonds are broken

20. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Electrons and Bonding  Electrons occupy energy levels called electron shells  Electrons closest to the nucleus are most strongly attracted  Each shell has distinct properties  The number of electrons has an upper limit  Shells closest to the nucleus fill first

21. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Electrons and Bonding  Bonding involves interactions between electrons in the outer shell (valence shell)‏  Full valence shells do not form bonds

22. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Inert Elements  Atoms are stable (inert) when the outermost shell is complete  How to fill the atom’s shells  Shell 1 can hold a maximum of 2 electrons  Shell 2 can hold a maximum of 8 electrons  Shell 3 can hold a maximum of 18 electrons

23. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Inert Elements  Atoms will gain, lose, or share electrons to complete their outermost orbitals and reach a stable state  Rule of eights  Atoms are considered stable when their outermost orbital has 8 electrons  The exception to this rule of eights is Shell 1, which can only hold 2 electrons

24. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Inert Elements Figure 2.5a

25. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 2.5b Reactive Elements  Valence shells are not full and are unstable  Tend to gain, lose, or share electrons  Allow for bond formation, which produces stable valence

26. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Bonds  Ionic bonds  Form when electrons are completely transferred from one atom to another  Ions  Charged particles  Anions are negative  Cations are positive  Either donate or accept electrons

27. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Ionic Bonds Figure 2.6 +– Sodium atom (Na) (11p + ; 12n 0 ; 11e – )‏ Chlorine atom (Cl) (17p + ; 18n 0 ; 17e – )‏ Sodium ion (Na + )‏Chloride ion (Cl – )‏ Sodium chloride (NaCl)‏ ClNaCl Na

28. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Ionic Bonds Figure 2.6, step 1 Sodium atom (Na) (11p + ; 12n 0 ; 11e – )‏ Chlorine atom (Cl) (17p + ; 18n 0 ; 17e – )‏ Cl Na

29. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Ionic Bonds Figure 2.6, step 2 Sodium atom (Na) (11p + ; 12n 0 ; 11e – )‏ Chlorine atom (Cl) (17p + ; 18n 0 ; 17e – )‏ Cl Na

30. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Ionic Bonds Figure 2.6, step 3 +– Sodium atom (Na) (11p + ; 12n 0 ; 11e – )‏ Chlorine atom (Cl) (17p + ; 18n 0 ; 17e – )‏ Sodium ion (Na + )‏Chloride ion (Cl – )‏ Sodium chloride (NaCl)‏ ClNaCl Na

31. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Bonds  Covalent bonds  Atoms become stable through shared electrons  Single covalent bonds share one pair of electrons  Double covalent bonds share two pairs of electrons

32. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Examples of Covalent Bonds Figure 2.7a

33. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Examples of Covalent Bonds Figure 2.7b

34. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Examples of Covalent Bonds Figure 2.7c

35. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Polarity  Covalently bonded molecules  Some are non-polar  Electrically neutral as a molecule  Some are polar  Have a positive and negative side Figure 2.8

36. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Bonds  Hydrogen bonds  Weak chemical bonds  Hydrogen is attracted to the negative portion of polar molecule  Provides attraction between molecules

37. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hydrogen Bonds Figure 2.9

38. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Patterns of Chemical Reactions  Synthesis reaction (A + B  AB)‏  Atoms or molecules combine to form larger ones  Energy is absorbed for bond formation (energy absorbing reactions)  Decomposition reaction (AB  A + B)‏  Molecule is broken down  Chemical energy is released  Ex: digestion of food

39. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Synthesis and Decomposition Reactions Figure 2.10a

40. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Synthesis and Decomposition Reactions Figure 2.10b

41. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Patterns of Chemical Reactions  Exchange reaction (AB + C  AC + B)‏  Involves both synthesis and decomposition reactions  Switch is made between molecule parts and different molecules are made

42. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Patterns of Chemical Reactions Figure 2.10c