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 Matter and Energy  Matter—anything that occupies space and has mass (weight)  Energy—the ability to do work  Chemical  Electrical  Mechanical  Radiant

3. 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

4. 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

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

6. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Identifying Elements  Atomic number—equal to the number of protons that the atom contains  Atomic mass number—sum of the protons and neutrons

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

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

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

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

27. 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

28. 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

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

30. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Patterns of Chemical Reactions  Synthesis reaction (A + B  AB)  Atoms or molecules combine  Energy is absorbed for bond formation  Decomposition reaction (AB  A + B)  Molecule is broken down  Chemical energy is released

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

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

33. 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

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