How many electrons do all atoms want in their outer shell? How do these atoms get those e-s in the...

• How many electrons do all atoms want in their outer shell?

• How do these atoms get those e-’s in the outer shell?

• How can you tell how many valence e-’s an atom has?

• If atoms gain e-’s, they become ____________ charged.

• If atoms lose e-’s, they become ____________ charged.

FLASHBACK

Unit 4

Ch. 20/21

To increase stability of the atomsTo increase stability of the atoms

Group 1 and 2 metals transfer electrons to Group 16 and 17 nonmetals to create ionic bonds.

Metals lose electrons & nonmetals gain electrons to achieve noble gas structure!

CaCl2

Calcium ion will give up its outer electrons to both chlorine atoms

Ca

ClCl+2

-1 -1

Mg

BrBr+2

MgBr2

H

OH

Oxygen only needs two electrons so hydrogen shares its one valence electron so that both atoms fill their outer shells.

Weaker bonds form

H2O

Ionic vs. Covalent

Video

Shows only valence electrons of atom with dots around the element's symbol

What’s the point?

P=1

N=0 1 e- H

P=20

N=20 Ca2 e- 8 e- 8 e- 2 e-

Nitrogen: N

Strontium: Sr

Water: H2O

1. What types of elements occupy space in groups 1 and 2?

2. How many valence e-’s do these groups have, respectively?

3. What will their ionic charges be, respectively, if they lose their valence e-’s?

4. Metals will _____________ e-’s. 5. Non-metals will ________________ e-’s. 6. What e-’s do the bonding? 7. Explain difference between ionic and

covalent bonds.

FLASHBACK

Bonding Worksheet:4. Na 5. Cl

7. Be 10. Ne

11. Mg

Covalent or ionic bond?12. HCl_________________________

14. AlO3________________________

Using electron dot diagrams, draw the ionic bonds…17. NaCl

Ionic vs. covalent... Which will win???

Investigating the difference between sugar and salt!

Salt!Sugar!

Who knew Chemical Bonding could be so cool????

Want to give it a try???Extra Credit by the end of the 9 weeks

(March 23th) for a Chemistry Rap Video!

Covalent Structures: make molecules and SHARE ELECTRONS

Example: H20, CO2, C12H22O11

same charges, so no strong attraction

Ionic Structures: make ionic crystals and TRANSFER ELECTRONS

Example: NaCl, KI, CaF2

+ and – charges make a STRONG attraction!

A. When positive and negative ions surround each other, they form tightly packed structures called ionic crystals or crystal latticesSubstances with network (ionic) structures are usually strong solids with high melting and boiling pointsSubstances made of molecules have lower melting and boiling points

What happens if it is not the neutral element.. But the ion??

e- diagram lose or gain e-? new (ion) e- diagram

Na

Cl

Mg

SECTION 1 REVIEW Pg. 606 # 4, 5

CHAPTER REVIEWPg. 626 # 4-6, 11, 14, 17, 18

1. Which of the substances has the lower melting point (which melted faster)? Was this what you expected? Why or why not?2. Relate your results to ionic and covalent bonding.3. On a molecular level, how do the bonds in sugar and salt differ?4. Why do atoms bond?5. Water (H2O) contains a(n) _________________ bond. Calcium oxide (CaO) contains a(n) ________________ bond.

EOC WORKBOOK!!!EOC WORKBOOK!!!

Pg. 38 (all)Pg. 38 (all)

Pg. 39 (all)Pg. 39 (all)

Pg. 36 (all)Pg. 36 (all)

Pg. 37 (all)Pg. 37 (all)

FLASHBACK

1. Table salt (NaCl) has what kind of bond?

2. Table sugar (sucrose, C12H22O11) has what kind of bond?

3. When heated, what happened to the bonds in sugar?

4. When heated, what happened to the bonds in salt?

5. Provide the electron dot structure for Barium (Ba), Iodine (I), and Cesium (Cs).

FLASHBACK

Review of Terms!

1. Cation: positively charged ion - Non metals or metals?

2. Anion: negatively charged ion- Non metals or metals?

1. Symbol: element being used2. Subscript: shows how many of the individual

atoms are presentex. O2 CO2 HBr

3. Coefficient Number: placed before the element or compound, distributed to entire compound

ex. 2HBr or 2H2 + O2 2H2O

4. Oxidation Number: same as “charge”, how many electrons atoms need to gain or lose (to become stable)

**get off of periodic table!!**write them on your P.T. (Al = +3)

The chemical symbols and numbers indicating the number of atoms contained in the basic unit of a substance

C6H12O6

Carbon = 6 atomsHydrogen = 12 atoms

Oxygen = 6 atoms

How many atoms of each element are present in 3 molecules of glucose?

C=18 H=36 O=18C=18 H=36 O=183 C6H12O6

The elements overall charges have to equal zero

Compounds have no net charge!!

Write the cation first with its charge, then the anion and its charge.

Al+3 F-1

Write the chemical formula, using subscripts to indicate how many of each ion are needed to make a neutral compound.

criss-cross method: Al+3 F-1 = AlF3

Balance the formula so the compound formed has a neutral charge

Examples:

Ca+2 + Br –1

Na+1 + S –2

Al +3 + Cl-1

Ionic compounds are formed by the strong attractions between cations and anions. Both ions are important to the compound’s structure, so it makes sense that both ions are included in the name

1. Name cation first (metal) 2. Name anion (nonmetal) 3. Drop the end of the anion & add suffix

–ideEXAMPLE: NaCl = sodium chloride

cationcation anionanion Balance Balance formulaformula

Compound Compound namename

Cs+1,cesium F-1,fluorine

Ba+2, barium Cl-1,chlorine

Al+3, aluminum S-2, sulfur Aluminum sulfide

Cesium Fluoride

Barium chloride

CsF

BaCl2

Al2S3

Uses prefixes!!!!Number of atoms

prefix

1 Mono-2 Di-3 Tri-4 Tetra-5 Penta-6 Hexa-7 Hepta-8 Octa-9 Nona-10 Deca-

If there is only one atom of the first element, it does not get a prefix

EX: BF3= boron trifluoride

Dihydrogen monoxide Dihydrogen monoxide = ????= ????

Dihydrogen Monoxide!!!!!!!!Why????Why????

If H20 is water, what is H204? 

Drinking, bathing, washing,

swimming…All kinds of things!

What’s in a name???How many people can you “bond” with!?

You must turn in to me a piece of paper with…1.Your element and it’s oxidation number2.A total of 6 IONIC COMPOUND formulas 3.AND the name of those compounds

My IonMy Ion What I am What I am bonding withbonding with

Chemical Chemical FormulaFormula

NameName

Fe+2 O-2 FeO Iron Oxide

Try these covalent molecules…

CO CO2

N5H8

TeBr2

Si3S7

Carbon Carbon monoxidemonoxideCarbon dioxideCarbon dioxidePentanitrogen octahydridePentanitrogen octahydride

Tellurium dibromideTellurium dibromideTrisilicon Trisilicon heptasulfideheptasulfide

1. How many oxygen atoms are there in bleach, NaClO, AKA sodium hypochlorite?

2. Acetone (CH3COCH3), or nail polish remover, has how many total hydrogen atoms?

3. How do you determine oxidation #’s?

4. What is the oxidation # of Al, O, & Cl ?5. Write ionic formulas: (find charges 1st then criss-cross!!)

Mg + F Be + N 6. Name the following compounds: N5H8 SrCl2

FLASHBACK

COVALENT:NONO2

N2OIONIC:

NaFZnClCaCl2

1. Electron Dot Diagram: 2. Pictorial Diagrams:

Hydrogen: H

Oxygen:

Water: H2O

H

O

OH

HCovalent Covalent bonds!bonds!

Chemical Changes

and Chemical Reactions

Occur when the size or shape of the substance is changed

Occasionally, the color can change, tooRegardless, the original substance(s) do not change

Evidences of Physical Changes:- Bending, stretching, heat, and cooling can all cause a

physical change ***All phase changes are physical changes

Occurs when there is a change in the Occurs when there is a change in the arrangement of atoms so that arrangement of atoms so that a different a different substance with different properties is substance with different properties is producedproduced

Very often, Very often, there is some there is some kind of kind of evidence evidence ((for example, for example, the formation the formation of a gasof a gas))

1. Formation of a gas2. Reaction with acids (like this picture of copper

reacting with nitric acid) 3. (Sometimes) a color

change can indicate a chemical change. - A good example of this is metal tarnishing

Is a neutralization reaction a chemical change?

1. Bubbles/fizzing/formation of a gas

2. Precipitate formed3. Energy change4. Color change5. Odor…

Chemistry Joke!If you're not part of the

solution…

You're part of the precipitate!

1. What is the main difference between a chemical and physical change?

2. If a reaction forms a gas, you know it is a ______________ change.

3. If something changes color, you know it’s a chemical change. True False

4. Name the four evidences of a chemical rxn.

5. Explain a situation in which bubbling occurs, but it is NOT a chemical change.

FLASHBACK

Why do you burp after drinking a Coke?

• Coke and other soft drinks are carbonated

• Carbonation occurs when carbon dioxide is dissolved in water or solution

• This gives the "fizz" to carbonated beverages

• Excess gas needs out of the stomach.. So we burp!

Excuse me…

Using the materials provided: 1. 2 pieces of Alka-Seltzer2. 1 film canister3. Water…you are to build a projectile!

Pick ONE question to answer and generate a hypothesis and WRITE IT DOWN…

Use an “If-Then” statement!

1. How does changing the volume of water effect the time/height of rocket “launch”?

2. How does changing the amount of Alka-Seltzer effect the time/height of rocket “launch”?

Lab ReportYou are to write a brief lab report on your experience…

- Skip lines between headings- Full sentences! Alka seltzer

TitleHypothesis: (your question)Data: Table? List?Conclusion: tell me what you learned (in paragraph form!)

1. What evidence did you see of a chemical reaction taking place? How does this relate to the lab?2. Refer back to your hypothesis… was it right or wrong?? Why??3. What would have done differently… or how would you make this lab better?

EOC WORKBOOK Pg. 41 (all)

A. An exothermic reaction __________________ heat.

B. An endothermic reaction __________________ heat.

C. ( A + B AB ) is an example of a _____________ reaction

FLASHBACK

Naming:2) P2O5 ___________________________3) Mg3N ___________________________5) SiO2 ____________________________6) BaCl2 _______________________________8) B2P9 _____________________________________

Formulas:14) aluminum nitride ____________________16) disulfur pentaphosphide ____________________17) potassium sulfide __________________________18) rubidium iodide ____________________________20) hexacarbon dichloride ______________________

Chemical Reactions and Chemical Reactions and Equations:Equations:

What do they mean?What do they mean?What do they show?What do they show?

During any chemical reaction, there is an energy change.

1. Exothermic reaction: heat is released during the reaction, gets hot!

2. Endothermic reaction: heat is absorbed during the reaction, gets cold!

Everyday Exothermic and Everyday Exothermic and Endothermic ReactionsEndothermic Reactions

Instant Cold Packs

Instant heat packs

•The airbag's inflation system reacts sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas. Hot blasts of the nitrogen inflate the airbag.

•AIRBAGS!The airbag's inflation system reacts sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas. Hot blasts of the nitrogen inflate the airbag.

Exothermic vs. Endothermic

Endothermic Reaction

A. Reactants: original substances entering a chemical rxn

- what you started with, on the left side

B. Products: resulting substances- what you end with, on the right side

Reactants Reactants Products Products

Endothermic vs. Exothermic Endothermic vs. Exothermic

Calcium Chloride vs. Sodium Bicarbonate…

who will win the temperature war???

Turn into me:Half sheet of paper

1. Synthesis: 2 substances combine to form 1 substance

A + B -> AB2. Decomposition: 1 substance breaks down

(decomposes) to 2 substancesAB -> A + B (opposite of

synthesis)3. Single Displacement: 1 element replaces another

A + BC -> AC + B4. Double Displacement: positive ion of one

compound replaces positive ion of anotherAB + CD -> AD + CB

1. 4Al + 3O2 --> 2Al2O3

2. Ca(OH)2 --> CaO + H2O

3. Zn + CuSO4 --> ZnSO4 + Cu

4. Cl2 + 2KBr --> 2KCl + Br2

5. BaCl2 + Na2SO4 --> 2NaCl + BaSO4

6. 2H2 + O2 --> 2H2O

SynthesisSynthesis

DecompositionDecomposition

Single DisplacementSingle Displacement

Single DisplacementSingle Displacement

Double Double DisplacementDisplacement

SynthesisSynthesis

Label the following equations: (4types)

1. Zn + HCl ZnCl2 + H2

2. Fe + O2 Fe2O3

3. SiO2 + HF SiF4 + H2O

4. FeS + HCl H2S + FeCl2

5. In lab yesterday, what gas produced the signature “popping” sound?

Single Displacement

Synthesis

Double Displacement

Double Displacement

FLASHBACK

You will be conducting reactions to produce 5 different common gases and observe their chemical and physical properties.

A. NaHCO3 + HCl NaCl + H20 + ______

B. Cu + 4HNO3 Cu(NO3)2 + 2H20 + 2 _____

C. NH4Cl + NaOH NaCl + H20 + ______

D. 2H2O2 2H2O + ____

E. Mg + 2HCl MgCl2 + ____

CO2

NO2

NH3

O2

H2

Section ReviewPg. 645 #1, 3

EOC REVIEWPg. 656#1-5,

11, 15

FLASHBACK

EOC WORKBOOKPg. 43 [all]

FLASHBACK

Chemical reaction - is the process of changing reactants to products by a chemical changeChemical reactions are symbolized by

Reactants Products

(s) solid; (l) liquid; (g) gas; (aq) aqueous are the physical states of the reactants and

products

___Mg(s) + __ O2(g) __ MgO(s)

The reactants which enter into a reaction. The products which are formed by the

reaction. The amounts of each substance used and each

substance produced.

2 2

We use subscripts to balance compounds

CaCl2

subscripts cannot be changed

We use coefficients to balance equations

2 NaCl + _ Ca(OH)2 2 NaOH + __ CaCl2

Goal: to get the same number of atoms on both sides of the equation

__ Al + __ O2 ___ Al2O3

__ NaCl __ Na + __ Cl2

__ Li + __ H2O __ LiOH + __ H2

A. A balanced chemical equation represents the process of a chemical reaction in which atoms are rearranged but not created or destroyed.

B. By balancing chemical equations, you show that mass is conserved…

Law of Conservation of Mass!

Mass is neither created nor destroyed Mass is neither created nor destroyed in an ordinary chemical or physical in an ordinary chemical or physical

reactionreaction

Mass of Reactants = Mass of Products

LAB: Looking at the…Law of Conservation of mass!!!

Balance the following equations:1. ___Zn + ___HCl ___ZnCl2 + ___H2

2. ___Fe + ___O2 ___Fe2O3

3. ___SiO2 + ___HF ___SiF4 + ___H2O

4. ___FeS + ___HCl ___H2S + ___FeCl2

5.What is the overall goal of balancing equations?

FLASHBACK

Balance the following equations:

3. __BeCl2 + __KOH __Be(OH)2 +__KCl

4. __S8 + __ O2 __ SO3

5. __H3PO4 + __Mg(OH)2 __Mg3(PO4)2 + __H2O

1. __S8 + __O2 __SO2

2. __ HgO __Hg + __ O2

FLASHBACK

Reaction Rates!Reaction Rates!

Reactions occur when Reactions occur when particles of reactants particles of reactants collide with energycollide with energy

1. Temperature: higher temperature, reaction rate increases1. Particles moving faster, more collision

between particles

2. Concentration: when reactants are more concentrated, rate of reaction increases1. More particles mean more collisions

3. Surface Area: more surface area, reaction rate increases

4. Catalyst: presence of catalyst speeds up reaction without being permanently changed[Inhibitor: slows down a reaction]

Video!

EOC WORKBOOKPg. 45 [# 2-6]Pg. 46 [# 1-6]

Make some observations of salt under a microscope!!

http://www.sciencenetlinks.com/lessons.php?BenchmarkID=4&DocID=173http://www.sciencenetlinks.com/lessons.php?BenchmarkID=4&DocID=173http://www.mos.org/sln/sem/sem.html