Catalyst – February 30/2, 2011 HOMEWORK OUT PLEASE Use what you learned yesterday to answer… 1. What types of elements tend to A. LOSE electrons : metals or nonmetals? B. GAIN electrons: metals or nonmetals? 2. Fill in the blanks to finish the analogy: Share is to c_v_ _ _n_ as t_ _ _s_ _ _ is to _______.

Remember  5 minutes of "free time"

FUN GRAPH FRIDAY!!! Listen for your name while you work – come up to Ms. Stroh’s desk when called. 1. Write ONE conclusion after looking at the graph. 2. Why do you think the author of the graph used different colors?

Today’s Agenda  Catalyst and Come See Your Grade  Homework Review  Similarities and Differences between Ionic and Covalent Compounds  Part One: Hunt and List Basic Characteristics  Part Two: Classify  Part Three: Analogies  Exit Question Optional HW (100 Extra Credit Points): Worksheet

Today’s Objectives  SWBAT describe the characteristics of ionic and covalent compounds.  SWBAT compare, contrast, and classify ionic and covalent compounds WELL!

Yesterday’s Exit Question 1. Anion = _______ charge, Cation = _______ charge 2. Stable ion for Te 3. LDS for Magnesium

HW Review (Pages 83-85) 1. Valence electrons are the electrons in the highest/outermost energy level of an atom. 2. The valence electrons largely determine the chemical properties of an element and are usually the only electrons used in chemical bonds. 3. The group number of a representative element in the periodic table is related to the number of valence electrons it has. True 4. An electron dot structure (LDS) is a diagram that shows the symbol of an element and its valence electrons as dots.

HW Review (Pages 83-85) 5. Argon (8ve), Calcium (2ve), Iodine (7ve) 6. In forming compounds, atoms tend to achieve the electron configuration of a noble gas, which (except for helium) has eight valence electrons. 7. Metallic atoms tend to lose valence electrons to produce a positively charged ion. Most nonmetallic atoms achieve a complete octet by gaining or sharing electrons. 8. A) Mg 1s 2 2s 2 2p 6 3s 2 B) Al 1s 2 2s 2 2p 6 3s 2 3p 1 C) K 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1

HW Review (Pages 83-85) 9. C 10. A 11. B 12. D 13. Pseudo noble gas configuration 14. Zn 1s 2 2s 2 2p 6 3s 2 2p 6 3s 2 2p 6 4s 2 3d On board

HW Review (Pages 83-85) 16. Atoms of most nonmetallic elements achieve noble gas electron configurations by gaining electrons to become anions, or negatively charged ions. 17. They have nearly full valence shells (5 or more ve) 18. Elements of the halogen family lose one electrons to become halide ions. False 19. A) 3 B) 2 C) 2 D) A) N 3- [Ne] B) O 2- [Ne] C) S 2- [Ar] D) Br 1- [Kr]

Guided Notes! CHARACTERSITICS OF IONIC AND COVALENT COMPOUNDS!

PART ONE: LIST BASIC CHARACTERISTICS

IONIC CHARACTERISTICS HUNT!

IONIC CHARACTERISTICS 1) METAL + NONMETAL 2) ELECTRONS ARE TRANSFERRED 3) HIGH MELTING AND BOILING POINTS 4) HARD, BRITTLE CRYSTALLINE SOLIDS AT ROOM TEMPERATURE 5) GOOD CONDUCTORS OF ELECTRICITY WHEN DISSOLVED IN WATER

Metal + Nonmetal

Electrons are Transferred

High Melting and Boiling Points

Hard, Brittle, Crystalline Solids

Conduct Electricity in Water

Characteristics of Ionic Substances Write them down! 1.Electrons are transferred 2.Bonds between metals (cations) and nonmetals (anions) KNO 2 METAL NON-METAL

More Characteristics of Ionic Substances Write them down! 3.They make crystals (usually room temp., brittle) 4.High melting points 5.Good conductors of electricity when dissolved in water (soluble in water)

Example of an Ionic Bond Chlorine steals one of sodium’s electrons

Some practical applications… What is an electrolyte? Do you think that Gatorade would conduct electricity? electricity o_id=31797&title=Electricity_From_Electrolytes An electrolyte is basically just a salt dissolved in water…but it’s more about the IONS of the salt!

Even more practical!  Humans’ skin is slightly ionic because of sweat that is produced…  Let’s see how one innovator took this fact to make a really cool invention…

COVALENT CHARACTERISTICS DRAW!

COVALENT CHARACTERISTICS 1) NONMETAL + NONMETAL 2) ELECTRONS ARE SHARED 3) LOW MELTING AND BOILING POINTS 4) LIQUIDS AND GASES AT ROOM TEMPERATURE 5) POOR CONDUCTORS OF ELECTRICITY

Nonmetal + Nonmetal

Electrons are Shared

Low Melting and Boiling Points

Liquids and Gases

Poor Conductors of Electricity

PART TWO: CLASSIFY COMPOUNDS AS IONIC OR COVALENT

How to Classify?  Look at info given as it relates to the Basic Characteristics 1. Kinds of elements? 2. What are electrons doing? 3. High or low melting/boiling points? 4. State of matter at room temperature? 5. Good or poor conductors of electricity?

Classification Examples 1. Sodium chloride (NaCl) 2. Compound with a melting point of - 72˚C (-98˚F)…BRRR!!!

Exit Question 1. Write 2 characteristics for ionic compounds. 2. Write 2 corresponding (related) characteristics for covalent compounds. 3. Classify the following as ionic (I) or covalent (C): a. Magnesium oxide (MgO) b. High boiling point c. Shared electrons TURN IN YOUR CATALYST PAPER AS YOU LEAVE CLASS!