Table of Contents

1. Table of Contents • Elements and Atoms • Atoms, Bonding, and the Periodic Table • Ionic Bonds • Covalent Bonds • Bonding in Metals

2. - Elements and Atoms The Building Blocks of Matter • Matter may consist of elements, compounds, or mixtures.

3. - Elements and Atoms Atomic Theory and Models • Dalton thought that atoms were like smooth, hard balls that could not be broken into smaller pieces.

4. - Elements and Atoms Atomic Theory and Models • Thomson suggested that atoms had negatively charged electrons embedded in a positive sphere.

5. - Elements and Atoms Atomic Theory and Models • Rutherford was surprised that a few particles were deflected strongly. This led him to propose an atomic model with a positively charged nucleus.

6. Learning Objective • Determine the number of valence of electrons of any atom of any element in the Main Groups of the Periodic Table. • Determine how the reactivity of elements is related to the number of valence electrons.

7. - Elements and Atoms Atomic Theory and Models (Lab Notebook) • It was determined that electrons orbited around the nucleus in certain patterns (called orbitals) based upon their energy level (amt. of energy they hold). • It was also discovered that the first orbital (closest to the nucleus) could have a maximum of 2 electrons. Each of the ones that followed could only have a maximum of 8 electrons. • The outermost electrons are called valence electrons. These are important for bonding and chemical reactions.

8. Phosphorus Example • Phosphorus’ atomic number is 15, so it has… • 15 protons and 15 electrons (since it’s neutral). • The circles surrounding the nucleus represent the different energy levels within the atom. +15

9. Valence Electron Practice (Lab Notebook)

10. - Atoms, Bonding, and the Periodic Table Valence Electrons and Bonding • The number of valence electrons in an atom of an element determines many properties of that element, and an atom with 8 valence electrons is very non-reactive because it cannot “use” anymore valence electrons.

11. - Atoms, Bonding, and the Periodic Table The Periodic Table • As the number of protons (atomic number) increases, the number of electrons also increases. As a result, the properties of the elements change in a regular way across a period.

12. Groups/Families of Elements Experiment • Goals- (1) Determine the chemical properties of how elements in the same group vs. a different group react with silver. (2) Determine the formulas for the compounds formed. • Procedure (Forming Silver precipitates/silver solids): • Add drops of silver nitrate and potassium chloride as indicated by the diagram (11:1 = 11 drops of silver nitrate & 1 drop of potassium chloride). Record results… • Properties of the compound that formed in your data table. • Proportion that produced the MOST precipitate. • Formula based upon the proportion (ex.- 6:6, 5:7, 7:5 = 1 of each = AgCl, 8:4 = Ag2Cl, 4:8 = AgCl2, 9:3 = Ag3Cl, etc.) • Rinse your Chemplate or use another one and repeat step 1 with potassium bromide. • Repeat with potassium iodide. • Repeat with potassium sulfide.

13. Data Table & Conclusions Conclusion- Which elements appear to be in the same group/family? Why?

14. End of Section:Atoms, Bonding, and the Periodic Table

15. Learning Objectives • Describe ions and how they form bonds between atoms. • Write the formulas and names of ionic compounds.

16. Formation of Magnesium Oxide • Charge of MgCharge of O Overall Charge

17. - Ionic Bonds Ions and Ionic Bonds • When an atom loses an electron, it loses a negative charge and become a positive ion. When an atom gains an electron, it gains a negative charge and becomes a negative ion.

18. Formation of Sodium Chloride • Charge of NaCharge of Cl Overall Charge

19. - Ionic Bonds Ions and Ionic Bonds • Ionic bonds form as a result of the attraction between positive and negative ions.

20. - Ionic Bonds Ions and Ionic Bonds • Ions are atoms that have lost or gained electrons. See page 23. • WHEN OPPOSITELY CHARGED IONS BOND, they form compounds with a 0 OVERALL ELECTRIC CHARGE and EACH ION HAS 8 VALENCE ELECTRONS (or the maximum amount)!!!

21. Writing Formulas for Ionic Compounds • The number afterthe element symbol tells you the number of atoms of that element! • Ex.- CaCl2 (1calcium ion & 2chloride ions)

22. Ionic Practice Problems

23. Ionic Practice Problems

24. Ionic Practice Problems

25. Ionic Practice Problems

26. Charge of Ions & Their Group Number: from the left (+) & from the right (-) not counting Group 18

27. Noggin Knockers/Secret Shortcut

28. The reason that most atoms (outside of hydrogen and helium) will form ions is that they want _________ valence electrons • 2 • 8 • 16 • 0

29. When an atom gains an electron, it forms a • Positive ion. • Negative ion. • Neutral ion. • A new element.

30. When an atom loses an electron, it forms an ion with a • Positive charge. • Negative charge. • Neutral charge. • No charge.

31. An ionic bond forms when oppositely charged ions • Disconnect. • Repel. • Attract. • Reconnect.

32. The overall charge for an ionic compound is always • Unknown. • Negative. • Positive. • 0 or neutral.

33. Ionic Review: Unknown Ion Demo & Silver Precipitates (Ion chart is on p. 23) • Demo: Potassium permanganate (KMnO4) reacts with glycerin (C3H8O3) in a delayed reaction to produce water, carbon dioxide, manganese dioxide, and potassium carbonate. The reason they KMnO4 is so reactive is due to the large number of oxygen atoms (4 of them) that are contained within that ionic compound. • These compounds are called oxidizers because they add oxygen to whatever they react with and cause that substance to lose electrons to the oxidizer. • Also, MnO4 is the negative ion in KMnO4. What is the charge of MnO4 (the permanganate ion)? • Expt: Determine the charge of a silver ion (Ag) for the precipitates you formed in the Families of Elements experiment: AgCl, AgBr, AgI, Ag2S • *Note that the ratio of the silver ion to the negative ion is different for silver sulfide (Ag2S) due to the fact that the sulfide ion has a different charge and is in a different group on the periodic table.

34. - Ionic Bonds Previewing Visuals • Before you read, preview Figure 17. Then write two questions that you have about the diagram in a graphic organizer like the one below. As you read, answer your questions. Formation of an Ionic Bond Q. What is an ionic bond? A. An ionic bond is the attraction between two oppositely charged ions. Q. What is the overall charge on an ionic compound? A. Overall, an ionic compound is electrically neutral.

35. - Ionic Bonds Salt • Click the Video button to watch a movie about salt.

36. - Ionic Bonds Links on Ionic Compounds • Click the SciLinks button for links on ionic compounds.

37. End of Section:Ionic Bonds

38. Noggin Knockers (10 points- 2 pts. each) • What are the two ways that ions can form from neutral atoms? • Explain how a sodium ion forms. Explain how a chloride ion forms. • What holds the ions together in the compound sodium chloride? • The formula for sodium sulfide is Na2S. Explain what this formula means in terms of the number of each ion. • Write the chemical formula for calcium chloride.

39. Noggin Knockers/Hwk. (10 points) • 1 (2 points)- Atoms gain or lose electrons to form ions. • 2 (2 points)- Sodium loses an electron to become a positive ion (Na+1) while chlorine gains that electron to form a negative ion (Cl-1) • 3 (2 points)- The attraction of opposite charges hold the ions together in any ionic compound. • 4 (2 points)- For Na2S means that there are 2 sodium ionsfor everyone sulfide ion. • 5 (2 points)-CaCl2, there is one calcium ion (Ca+2) and two chloride ions (Cl-1) to create calcium chloride (overall charge = 0)

40. Learning Objectives • State what holds covalently bonded atoms together. • Predict how molecular compounds are bonded together. Molecular compoundsare those with covalent bonds instead of ionic bonds.

41. Covalent Bonding Examples (Lab Notebook) • CO2 • NH3

42. Noggin Knockers

43. Covalent Bonds- Determine the # of valence electrons for each atom and then arrange the electrons so that each atom has the correct number when sharing each other’s electrons. (Lab Notebook) • Examples: CO2 NH3 • Cl2 • F2 • H2 • O2 • N2 • CO (tough one) • H2O (Oxygen is the central atom) • For the following models, determine the number of “extra” electrons 1st based upon the charge, know that the central atom is the first one in the formula, & sulfur and phosphorus can have more than 8 valence electrons: • (8) SO4-2, (9) CO3-2, (10) PO4-3, (11) NH4+1

44. Learning Objectives • State what holds covalently bonded atoms together. • Predict how molecular compounds are bonded together. Molecular compoundsare those with covalent bonds instead of ionic bonds.

45. Noggin Knockers- Ionic & Covalent Bonding

46. Covalent Bonds- Determine the # of valence electrons for each atom and then arrange the electrons so that each atom has the correct number when sharing each other’s electrons. (Lab Notebook) • If finished with the ones below try: S2, I2, &CH4then try 8-11. • Cl2 • F2 • H2 • O2 • N2 • CO (tough one) • H2O (Oxygen is the central atom) • For the following models, determine the number of “extra” electrons 1st based upon the charge, know that the central atom is the first one in the formula, & sulfur and phosphorus can have more than 8 valence electrons (up to 12 valence electrons): • (8) SO4-2, (9) CO3-2, (10) PO4-3, (11) NH4+1

47. - Covalent Bonds How Covalent Bonds Form • The force that holds atoms together in a covalent bond is the attraction of each atom’s nucleus for the shared pair of electrons.

48. - Covalent Bonds How Covalent Bonds Form • An oxygen molecule contains one double bond (2 pairs of shared electrons), while a carbon dioxide molecule has two double bonds. A nitrogen molecule contains one triple bond (3 pairs of shared electrons).

49. Covalent Bonding Review: Think-Pair-Share • How many valence electrons do all atoms but Hydrogen and Helium want? • Covalent bonding involves the _______ of electrons as oppose to forming oppositely charged ions. • A single covalent bond involves ____ pair(s) of shared electrons, while a double bond involves ____ pair(s) of shared electrons. • These shared electrons are attracted to the other atom’s positively charged ________.

50. Noggin Knockers