1. Basic Chemistry

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

3. 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. Atomic Structure Nucleus Protons (p+) Neutrons (n0) Outside of nucleus
Electrons (e-)
Figure 2.1

5. Atomic Structure of Smallest Atoms
Figure 2.2

6. Identifying Elements
Atomic number—equal to the number of protons that the atom contains
Atomic mass number—sum of the protons and neutrons

7. Isotopes and Atomic Weight
Have the same number of protons
Vary in number of neutrons
Figure 2.3

8. Isotopes and Atomic Weight
Close to mass number of most abundant isotope
Atomic weight reflects natural isotope variation

9. Radioactivity Radioisotope Heavy isotope Tends to be unstable
Decomposes to more stable isotope
Radioactivity—process of spontaneous atomic decay

10. Molecules and Compounds
Molecule—two or more like atoms combined chemically
Compound—two or more different atoms combined chemically
Figure 2.4

11. Chemical Reactions Atoms are united by chemical bonds
Atoms dissociate from other atoms when chemical bonds are broken

12. 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. Electrons and Bonding
Bonding involves interactions between electrons in the outer shell (valence shell)
Full valence shells do not form bonds

14. 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. 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. Inert Elements
Figure 2.5a

17. 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
Figure 2.5b

18. 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. + – Ionic Bonds Na Cl Na Cl Sodium atom (Na) (11p+; 12n0; 11e–)
Chlorine atom (Cl) (17p+; 18n0; 17e–)
Sodium ion (Na+)
Chloride ion (Cl–)
Sodium chloride (NaCl)
Figure 2.6

20. Ionic Bonds Na Cl Sodium atom (Na) (11p+; 12n0; 11e–)
Chlorine atom (Cl) (17p+; 18n0; 17e–)
Figure 2.6, step 1

21. Ionic Bonds Na Cl Sodium atom (Na) (11p+; 12n0; 11e–)
Chlorine atom (Cl) (17p+; 18n0; 17e–)
Figure 2.6, step 2

22. + – Ionic Bonds Na Cl Na Cl Sodium atom (Na) (11p+; 12n0; 11e–)
Chlorine atom (Cl) (17p+; 18n0; 17e–)
Sodium ion (Na+)
Chloride ion (Cl–)
Sodium chloride (NaCl)
Figure 2.6, step 3

23. 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. Examples of Covalent Bonds
Figure 2.7a

25. Examples of Covalent Bonds
Figure 2.7b

26. Examples of Covalent Bonds
Figure 2.7c

27. 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. Chemical Bonds Hydrogen bonds Weak chemical bonds
Hydrogen is attracted to the negative portion of polar molecule
Provides attraction between molecules

29. Hydrogen Bonds
Figure 2.9

30. 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. Synthesis and Decomposition Reactions
Figure 2.10a

32. Synthesis and Decomposition Reactions
Figure 2.10b

33. 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. Patterns of Chemical Reactions
Figure 2.10c