Bellwork 12/4/2012. Homework. Do the alkali metals gain, lose or share electrons? How many? Read. Reviewing Key Concepts 5

Bellwork 12/4/2012 Do the alkali metals gain, lose or share electrons? How many? Read Homework ibooks 7.1 Chemical Bonding (Intro. To chemical bonds) OR1.2 Valence Electrons; Valence Electrons and Lewis Structures UOS #5 Item #20 Reviewing Key Concepts 5 UOS #5 Item #19

Reading for Science Class 101 Two choices: 1. Net Texts App UOS #1 Item #1 Textbook Flexbook PDF 2. ibooks App Chapters and Sections Ex. Chapter 7 Section 1 Chemical Bonding (reactions to chemical bonds)

Lewis Structures 1) Find your element on the periodic table. 2) Determine the number of valence electrons. 3) This is how many electrons you will draw.

Lewis structures for oxygen, fluorine, the hydrogen sulfate anion, and formamide The Lewis structure of water

Lewis Structures Find out which group (column) your element is in. This will tell you the number of valence electrons your element has. You will only draw the valence electrons. www.chem4kids.com

Groups - Review Group 1 = 1 electron Group 2 = 2 electrons Group 8 = 8 electrons Except for He, it has 2 electrons Each column is called a group www.chem4kids.com Each element in a group has the same number of electrons in their outer orbital, also known as shells. The electrons in the outer shell are called valence electrons

Valence Electron Analogy This all Georgia Tech 12-way over Florida Skydiving Center in Lake Wales, FL on January 1st, 2005 included members of the 4-way and 2-way teams GT Airlock, GT Fusion, Inviscid, and GT Propel.

Octet Rule The octet rule is a chemical rule of thumb that states that atoms of low (<20) atomic number tend to combine in such a way that they each have eight electrons in their valence shells, giving them the same electronic configuration as a noble gas. The rule is applicable to the maingroup elements, especially carbon, nitrogen, oxygen, and the halogens, but also to metals such as sodium or magnesium.

Lewis Structures 1) Write the element symbol. 2) Carbon is in the 4 th group, so it has 4 valence electrons. 3) Starting at the right, draw 4 electrons, or dots, counterclockwise around the element symbol.

Lewis Structures 1) Check your work. 2) Using your periodic table, check that Carbon is in the 4 th group. 3) You should have 4 total electrons, or dots, drawn in for Carbon.

Lewis Structures On your worksheet, try these elements on your own: a) H b) P c) Ca d) Ar e) Cl f) Al

If have more than 4 valence electrons, element would want to electrons to reach the stable 8 valence electrons. If less than 4 valence electrons, element would want to electrons to reach the stable 8 valence electrons. If two elements work together, can both reach the stable 8 valence electrons.

Challenge Questions: What can you determine based on the number of valence electrons? How can you quickly determine how many valence electrons an element has?

Take Home Message Octet Rule =8 valence electrons, stable Can gain, lose or share electrons to get 8 valence electrons Metals=lose e Non-metals=gain e Forms chemical bond during chemical reaction to make new substances

To Do: Complete the Lewis Structure Worksheet You should know how to draw Lewis Structures for the first 20 elements.

Bellwork 12/5/2012 What are valence electrons? Homework SYNC ipads (even if you already did!) Quiz Monday 12/10 Valence electrons, bonding, and Lewis Diagrams

HW check Reviewing Key Concepts 5 UOS #5 Item #19

Challenge Questions: What can you determine based on the number of valence electrons? How can you quickly determine how many valence electrons an element has?

Bonding 101 Metals=Lose electrons Left PT Non-metals=Gain electrons Right PT Reactivity of Non-metals: Metals bond with Non-metals Gain electrons (ionic bond) Non-metals bond with Non-metals Share electrons (covalent bond)

Introduction to Ch. 5 Atoms and Bonding Worksheet

Bellwork 12/6/2012 Why are valence electrons held on the most loosely? Homework SYNC ipads (even if you already did!) Read and take notes ibooks 7.2 Chemical Bonding (Ionic Bonds) OR1.2 Ionic Compounds; Introduction and Ionic Bonding UOS #5 Item #21 Quiz Monday 12/10 on Chapter 5, Sections 1 and 2 Valence electrons, bonding, and Lewis Diagrams

Ions are CHARGED Negative ions Positive ions Polyatomic ions

Overall charge of NaCl?

Ionic Bond A very strong attraction...

Using Figure 8, which ions would you expect would form a compound?

How many sodium ions would be present in the compound sodium phosphate?

How many sodium ions would be present in the compound sodium sulfide?

Ratios How many tires? Doors? Engines? T 4 D 2 E Would the car be the same if you changed the number of tires? Doors? Engines? What if 3 cars? What would new formula be? What if no engine?

Ratios in Chemical Formulas MgCl 2 What is the ratio of magnesium ions to chloride ions? CaCO 3 What is the ratio of calcium ions to carbonate ions?

Introduction to Ch. 5 Atoms and Bonding Worksheet

Bellwork 12/7/2012 Draw using a valence electron dot diagram what would happen if magnesium and oxygen got near each other. Homework Read and take notes Ck-12 ibooks 7.2 Chemical Bonding (Ionic Bonds) OR 1.2 Ionic Compounds; Properties of Ionic Compounds UOS #5 Item #21

Introduction to Ch. 5 Atoms and Bonding Worksheet

How many sodium ions would be present in the compound sodium phosphate?

How many sodium ions would be present in the compound sodium sulfide?

Return Tests Most commonly missed?s

Bellwork 12/10/2012 Magnesium chloride: How many atoms of magnesium? Chloride? (Hint: Use periodic table to determine number of valence electrons.) Homework Do Ionic Bonds worksheet (both sides!)

Quiz Time!

Use the PT and figure to ID the charges of the ions in each compound. Draw each compound and write the chemical formula for each. 1. Sodium bromide 2. Lithium oxide 3. Magnesium sulfide 4. Aluminum fluoride 5. Potassium nitrate 6. Ammonium bicarbonate *How did you know how many of each ion to write in the formula?

Make the compounds below: Turn in when complete with ALL group members names 1. Sodium bromide 2. Lithium oxide 3. Magnesium sulfide 4. Aluminum fluoride 5. Potassium nitrate 6. Ammonium bicarbonate

6. What do you notice about the ending of the second ion s name? 1. Write the formula for each compound. 2. How did you know how many of each ion to write in the formula? 3. What do the different objects represent? 4. What happens to the electrons in the ions? 5. What do you notice about the ordering of the ions in the names of each compound?

KEY Pair positive and negative ions in ratios that result in neutral ionic compounds: NaBr Li 2 O MgS AlF 3 KNO 3 NH 4 HCO 3

Safari Montage Acid Rain http://10.14.3.88/safari/montage/play.php?ke yindex=25 26 min.

Bellwork 12/12/2012 What is an ionic bond? What causes this bond to happen? Homework Read ibooks 7. 3 Chemical Bonding (Covalent Bonds) OR1.1 The Covalent Bond UOS #5 Item #22

HW check Ionic Bonding worksheet

Naming Ionic Compounds Positive ion THEN Negative ion Positive Name of the positive ion Negative If single atom, change ending to ide If polyatomic, change ending to -ite or -ate Examples CaO Calcium oxide NH 4 SO 4 Ammonium sulfate

Ions: Hard, brittle crystals with high melting points Going back What was a crystalline solid? Crystals so ordered and so strongly attracted to each other, that it takes a lot of heat to melt them When dissolved in water, conduct electricity! Why does it have to be dissolved in water? To think about for later if ionic bonds are so strong, how come everyday old water can break the bonds apart?

Dissolving 101 http://www.northland.cc.mn.us/biology/biol ogy1111/animations/dissolve.html

Safari Montage Acid Rain http://10.14.3.88/safari/montage/play.php?ke yindex=25 26 min.

Bellwork 12/13/2012 Draw the valence electron dot diagram for barium chloride. How many protons does chloride have? How many electrons does chloride have? Homework Quiz 12/20 dot diagrams, ionic and covalent bonds, polar/nonpolar

Dissolving 101 http://www.northland.cc.mn.us/biology/biol ogy1111/animations/dissolve.html

Chemical Formula Review Sub script= ratio of atoms of element Super script= charge of atoms (ions)

Safari Montage Bill Nye Electrical currents 21 min. http://10.14.3.88/safari/montage/play.ph p?keyindex=1310&location=local

Bellwork 12/14/2012 Name the following ionic compounds: Li 2 O NaF NH 4 Cl Homework Covalent bonding worksheet Quiz on Chapter 5, Section 3 12/20 dot diagrams, ionic and covalent bonds, polar/nonpolar

If give away or take up an electron, IONIC BONDING If SHARE electrons COVALENT BONDING Working closer together Nonmetals and nonmetals Share an electron pair forming a neutral molecule

Covalent bonding in fluorine Why can t metals do this? In a fluorine atom, how many valence electrons does fluorine have? In a fluorine molecule, how many valence electrons does fluorine have?

What would happen if two oxygen atoms combined in the same way? How many valence for oxygen atom? For molecule? How can we fix this? Double bond What about for nitrogen? Triple bond

Molecular Compounds (compounds made of ) Lower boiling points, lower melting points, don t conduct electricity Most are liquids or gases at room temperature Water, oxygen gas, carbon dioxide No charged particles to move around

What if the molecular compound doesn t share equally? One atom will hog electrons Clearly needs to return to kindergarten Each atom will have slight electrical charge Polar covalent bond Electrons are shared unequally Nonpolar covalent bond Electrons are shared equally What about the overall molecule? Just because the bonds are polar, is the molecule polar?

Bellwork 12/17/2012 Which is stronger: ionic or covalent bonds? Why? Read and take notes Homework ibooks 7.3 Chemical Bonding (Metallic Bonds) OR 1.3 Types of Forces of Attraction for Solids UOS #5 Item #23 Quiz on Chapter 5, Section 3 12/20 Chapter 5 Test: January 14 th

HW check Covalent Bond Worksheet

To Do: Key Terms Worksheet

Presentations Compare and Contrast Molecular vs. Ionic Compounds Covalent/ionic bond Charge? Share vs. Transfer Metals + Nonmetals/Non-metals + Nonmetals Strong/weak Number of bonds, polar vs. nonpolar Composed of molecules vs. ions Melting point, conductivity, properties? WHY???

Bellwork 12/18/2012 Draw the valence electron dot diagram for a diatomic chlorine molecule. Homework Reviewing Key Concepts 5.1 UOS #5 Item #24 Quiz on Chapter 5, Section 3 12/20 Chapter 5 Test: January 14 th

KEY TERMS/Concept Map 1. Metallic 2. Polar 3. Valence 4. Alloy 5. Molecule 6. Ion 7. Crystal 8. Ionic bond 9. Nonpolar 10. Double bond Covalent bond Chemical bond formed when two atoms share electrons

Bellwork 12/19/2012 A metal consists of a positively charged metal ions embedded in a. Homework Finish Oil Spill worksheet Quiz on Chapter 5, Section 3 tomorrow! Chapter 5 Test: January 14 th

Reviewing Key Concepts 5.1 1a. What is an alloy? Mixture of two or more elements that has the properties of a metal. 2b. Explain how metal atoms form metallic bonds. What role do valence e- play? Each metal atom contributes a positive ion and one or more loosely held valence electrons. 2c. How does a metallic bond differ from an ionic bond? Metallic bond attraction b/t positive metal ion and the electrons around it. Ionic bond attraction b/t positive and negative ions. 3a. 4 properties of metals what accounts for these properties? Ability change shape; Heat conductivity; Electrical conductivity; Luster The loosely held valence electrons which allow ions and valence electrons in metals to move

Oil Spill!

Bellwork 12/20/2012 Are ionic or covalent bonds stronger? Which has a higher boiling point? Why doesn t the compound with the stronger bond have the higher boiling point? Homework Finish Reviewing Key Terms 5 worksheet Chapter 5 Test: January 14 th

Oil Spill!

Oil Spill HW check!

Quiz Time Covalent Bonding Quiz Ch. 5 Sec. 3

Classwork 12/20 Do Reviewing Key Terms 5 worksheet

Bellwork 1/7/2013 How can the large amount of surface tension in water be explained? Chapter 5 Test on 1/14 Homework

Polarity underlies a number of physical properties including surface tension, solubility, and melting- and boilingpoints. Diagram of the forces on two molecules of liquid

The cohesive forces among the liquid molecules are responsible for this phenomenon of surface tension. In the bulk of the liquid, each molecule is pulled equally in every direction by neighboring liquid molecules, resulting in a net force of zero. The molecules at the surface do not have other molecules on all sides of them and therefore are pulled inwards. This creates some internal pressure and forces liquid surfaces to contract to the minimal area.

Surface tension: Water has extremely high surface tension. Surface tension can be defined as the force per unit length pulling perpendicularly to a line in the plane of the surface. Because of its high surface tension, water can support fairly large objects placed carefully on its surface. Surface tension is due to the water-water attraction (cohesion) of its molecules relative to the water-air molecule interactions (adhesion). Surface tension can be greatly affected by certain solutes such as fatty acids and lipids because they may become concentrated at interfaces. These "surfactant" molecules usually have both polar and nonpolar regions.

Classwork Stations Count off in groups of 7

Bellwork 1/8/2013 Why does electrical conduction work with dissolved ionic compounds but not molecular compounds? Homework Stations Lab due tomorrow Chapter 5 Test on 1/14

HW check Reviewing Key Terms 5

Classwork Stations Count off in groups of 7

Bellwork 1/9/2013 Why don t water and oil mix? Homework Show started studying (something written) Chapter 5 Test on 1/14

Metallic Bonding Positively charged nucleus with valence electrons freely flowing around (a sea of valence electrons) Weakest bond of all which is why metals are so malleable Also why can conduct heat and electricity so well

Alloys Mixture with at least one metal Usually stronger and less likely to react than metals on their own Iron is strong but rusts easily so used to make steel (an alloy of iron)

Bellwork 1/10/2013 Give three examples of polyatomic ions. Chapter 5 Test 1/14 Homework

Bellwork 1/14/2013 Does an atom of sodium have the same level of reactivity as an ion of sodium? Why or why not? Homework Chapter 5 Test 1/9

Bellwork 12/8/2008 Arrange the four types of bonding we have talked about in order from strongest to weakest. Key Terms worksheet Homework Chapter 5 Test on 12/12

1. Ion 2. Loses negative charge and becomes a postive ion 3. Gains negative charge and becomes negative ion 4. Polyatomic ions 5. a) +1 b) Na+ c) 2+ d) Mg+2 e) -1 f) Cl- g) 2- h) SO42-6. 2 more electrons than protons; charge is 2-7. Na becomes positive, Cl becomes negative 8. Ionic bond attraction between 2 oppositely charged atoms 9. Ex NaCl 10. Chemical formula 11. True 12. 2 is subscript two chloride atoms per Mg 13. False 14. When negative ion is single element 15. Hard, brittle, crystal, high melting point, can conduct electricity when in solution or melted 16. Crystal 17. Every ion is attracted to ions of opposite charge around it 18. Ionic bonds are strong, need lots of E to break 19. Solids 20. Solids are tightly bound, no energy can flow; when bonds broken, can move freely and conduct electricity

1. 7 2. 7 3. 5 4. Reactive needs 3 valence electrons to be stable 5. Nonmetal 6. Highest energy electrons and most loosely held 7. Chemical bond 8. Transferred or shared 9. If less than eight electrons in valence shell, will likely react 10. Same number of valence electrons 11. Lose 12. Gain; share

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