Catalyst of Love 2011 Monday Mystery Element! 1. Easily magnetized 2. Important for human nutrition by preventing anemia 3. Can become radioactive and emit gamma rays (can treat cancer)

Catalyst – October 2(2), 2010 Monday Mystery Element! 1. Easily magnetized. 2. Important for human nutrition by preventing anemia. 3. Can become radioactive and emit gamma rays (can treat cancer). COBALT!

Catalyst – September 3(7), 2011 WAY BACK WEDNESDAY! 1. Write the 5 (or 6) steps of the Scientific Method in order. 2. What metric unit would you most likely use to measure the size of a T-bone steak?

Today’s Agenda  Catalyst  Welcome to Unit 3!!!  Notes  Lewis Dot Structures  Stable Ions and Oxidation Numbers  Octet Rule  Exit Question HW: Workbook Pages HONORS HW: Workbook Pages 81-84

Today’s Objectives  SWBAT describe a chemical bond.  SWBAT draw Lewis Dot Structures for atoms and ions.  SWBAT use the octet rule to predict the stable ion an atom will form in a chemical bond.

Happy Valentine’s Day… Scientifically!  hotos/phyz/sets/ /show/ hotos/phyz/sets/ /show/

Front DoorProjector 2 nd Period Group 3 Richielle, Michael, Amanda, Group 2 David, Alexis, Spencer, Group 1 Frank, Jordan, Zain, Andre Group 6 Phoebe, Johnny, Baily, Don Group 4 Casey, Marissa, Tywanda Group 9 NO STUDENTS Group 8 Casey, Chris, Karen Group 7 NO STUDENTS Group 5 Kyle, Josh, Ebony, Caroline

Front DoorProjector 3 rd Period Group 3 Jessica, Paula, Daniel, Jill Group 2 Chad, Danielle, Victoria Group 1 Jamal, Ja’Shion, Destiny, A’Lena Group 6 Kat, Kendell, Julia, Carolina Group 4 Ciara, Epiphany, Nadia, Earnest Group 9 NO STUDENTS Group 8 NO STUDENTS Group 7 NO STUDENTS Group 5 Robert, Gilberto, Katelyn,

Front DoorProjector 4 th Period Group 3 Gecoba, Cedric, India, Kasey Group 2 Patrion, William, Mignon, Group 1 Kendall, Eugene, Gino, Adriona Group 6 Jessie, Tarje, Jamie, Karla Group 4 Shannon, Nick, Amber, Centoria Group 9 NO STUDENTS Group 8 NO STUDENTS Group 7 NO STUDENTS Group 5 Darrell, Carlee, Donya,

Unit 3: Chemical Hook-Ups  In this unit, you will be learning about how atoms hook-up, or bond. The unit will include…  Lewis Dot Structures: Octet Rule, Stable Ions, Number of Bonds  Ionic Compounds vs. Covalent Compounds  Formulas and Names for Compounds  Chemistry.com profile and Speed Dating

What is a compound? Key Point #1: A compound results from interaction between valence electrons of different atoms.

Bonding  Key Point #2: There are two main ways that valence electrons interact between atoms to create chemical bonds: By completely transferring them to another element  Ionic Bond By sharing electrons with another element  Covalent Bond

Chemical Bond Spotlight: NaCl (table salt) 2 different elements:  Sodium (Na)  Chlorine (Cl) 1 compound:  Sodium chloride (NaCl) NaCl NaCl

Chemical Bond Spotlight: NaCl (table salt) Let’s see a video!

NOTES: LEWIS DOT STRUCTURES!

Valence Electrons  Valence electrons are the electrons in the outermost energy level NUCLEUS ALL TOGETHER, SODIUM HAS 11 ELECTRONS. SODIUM HAS 1 VALENCE ELECTRON P=11 N=12

Don’t Forget! Valence Electrons  Electrons in the outermost level or shell of the atom are the ones that determine the chemical reactivity of an element  Outer s and p electrons  These electrons are involved in bonding

Lewis Dot Structures Key Point #3: Lewis Dot Structures only show the number of valence electrons in an atom.  Valence electrons are the only electrons involved in bonding  Valence electrons are the most important electrons

Drawing Lewis Dot Structures 1. Write element symbol. 2. Determine number of valence electrons. 3. Place single dot on right side and add single dots counterclockwise. EXAMPLES COMING UP…

LDS Example 1: Sodium (Na) 1. Write element symbol. 2. Determine number of valence electrons. 3. Place single dot on right side and add single dots counterclockwise.

LDS Example 2: Neon (Ne) 1. Write element symbol. 2. Determine number of valence electrons. 3. Place single dot on right side and add single dots counterclockwise.

You try! 1. Boron 2. Oxygen 3. Lithium

Lewis Dot Sructures What do the Lewis Dot Structures have in common?!?!?

I have a couple QUESTIONS… 1. What kind of charge does an electron have?  (-1) 2. What kind of charge does an entire atom have?  Neutral (positives = negatives)

First thing you need to know about ionic bonds….  Key Point #4: An ion is an atom that has gained or lost an electron. Cation = positive ion (+) Anion = negative ion (-) + -

Types of ions  Cation – a positive ion (+)  “t” looks like (+)  Anion – a negative ion (-)  “n” or onion for negative

Formation of Negative Ions (ANIONS)  Imagine that electrons are pieces of poop  Is poop is flying into your yard (an atom’s energy levels) a positive or negative thing?  So…if poop lands in your yard, are you more positive or more negative? So…NEGATIVE ions are formed when an atom GAINS one or more electrons! -

Formation of Positive Ions (CATIONS)  Imagine that electrons are pieces of poop  Is poop in your yard (an atom’s energy levels) a positive or negative thing?  So…if you get rid of the poop in your yard, are you more positive or more negative? + So…POSITIVE ions are formed when an atom LOSES one or more electrons!

Practice Questions 1. If an atom gains an electron it will have a ___________ charge. 2. If an atom loses an electron it will have a ___________ charge. 3. If chlorine gains 3 electrons it will have a _______ charge. NEGATIVE POSITIVE 3-

Ions! Cl loses 4 Electrons What is the stable ion?

Ions! Cobalt gains 2 electrons What is the stable ion?

Ions! Si 3- What happened… gain or lose… how many?

Ions Si 3- Silicon gains 3 electrons How many total electrons does Si have now?

Practice Problems – Write all down!  Write down the stable ion that will form for the following: 1. Sr gains 5 electrons 2. Phosphorous loses 1 electron  Then, answer how many electrons TOTAL will they have now?

Practice Problems – Write all down! How many TOTAL electrons do the following ions have? 1. Cl Li Xe O Zn 5-

Octet Rule  What is different about the valence shells of the elements on the Left and those on the Right?  The noble gases have full valence shells, the other atoms do not… Octet Rule – Elements are most stable when they have the electron configuration of a noble gas (Key Point next…)

Key Point #5: The octet rule says that atoms are most stable when they have a full valence shell (2 or 8 valence electrons). 1. Atoms can gain or lose electrons to become stable (happy) 2. Atoms with 5 or more valence electrons will GAIN electrons to become stable (happy) 3. Atoms with 3 or less valence electrons will LOSE electrons to be stable (happy) Octet Rule

Octet Rule - Examples  How many electrons will the following atoms gain or lose to become stable (happy)? How many TOTAL electrons will the atom then have? What is the STABLE ION? 1. F 2. Se 3. N 4. Ca

Octet Rule – Examples Element# e- Gained/Lost Total electrons Stable Ion Formed Bromine Selenium Nitrogen Calcium

Need extra practice? Try these…  How many electrons will the following atoms gain or lose to become stable (happy)? How many TOTAL electrons will the atom then have? What is the STABLE ION? 1. P 2. Kr 3. Ca 4. I 5. K

Worksheet for Class or HW Half Shee – eet! Take care of your bidness and complete it tonight!

Exit Question 1. Anion = _______ charge, Cation = _______ charge 2. What is the STABLE ION that will form for the following elements? (Give the oxidation number)  Te 4. Draw the LDS for the following elements:  Magnesium HW: Workbook Pages HONORS HW: Workbook Pages 81-84