have you ever heard the word bonding before?

Have you ever heard the word bonding before?

If you have never heard it before write down what you

think it means?

If so, where did you hear it and what does it mean?

Bonding is what keeps elements

and ions of compounds together!!!

What’s the difference between an Element and a

Compound?Give an example of each

and explain why.

ElementsAn element is a substance that

cannot be broken down into different substances.

It is the smallest form of matter that has the same characteristics of that substance.

Examples: Au (gold), Na (sodium) etc.

COMPOUNDSDefine what a compound is?

Two or more DIFFERENT atoms (elements) that are chemically bonded together because of a chemical reaction. We use chemical formulas to represent compounds. Can you think of any…?H2O (Wudder) CO2 (Carbon Dioxide)

CH3COOH + NaHCO3 ===> CH3COONa + H2O + CO2

A Element

A Elements

C Mix of Element

s

D Mixture of

Compounds

E Mix of Elements/ Compounds

B Compounds

1

654

32

A New Language

Let’s do the Vial Lab!

We will talk about4 TYPES OF BONDS

IONIC COVALENTMETALLICHYDROGEN

(Ions)

(Sharing valence electrons)

(Metals)

(Ions)

IONIC BONDS• Form between ions

with opposite charges: + and -. (a metal and a non-metal)

• They bond because the opposite charges are attracted to each other. (Think magnets!!!)

IONIC BONDSLike charges repel each other!Ions and ionic bonds form because electrons are transferred from one atom to the other

Properties ofIONIC BONDS

• Ionic compounds have high melting and boiling points.

• These are very strong bonds.

• An example is Na+1 + Cl-1 = NaCl (salt)

NaCl Melting point 801 °C NaCl Boiling point1465 °C

http://en.wikipedia.org/wiki/File:Halite(Salt)USGOV.jpg

IONIC BONDSOnly certain ratios (combinations) of elements

result in the formation of Ionic compounds.

For ex: Lithium (Li) will react with Fluorine (F) to form LiF.

BUT, it will NOT form LiF2, LiF3, etc.

Magnesium (Mg) will react with Fluorine to form MgF2.

BUT, it will NOT form MgF, MgF3, etc.

IONIC BONDS• When writing a chemical formula for an

ionic compound: *The charges have to balance to create a neutral compound.*

IONIC BONDS• For example: - With salt the charges are both 1: Na+1 and Cl-1

So we just need one of each ion to make the compound neutral

= the ratio is 1:1 = NaCl

IONIC BONDS• What if the charges are not the same

number??? - Like Li+1 + O-2

Here you will not have a 1:1 ratio. You need to balance the chemical formula…

IONIC BONDS• What could you do to get the charges

to cancel out if you wanted to form this ionic compound???

Li+1 + O-2

ANSWER: You would need to use 2 Li+1 for every O-2!!!= Li2O

IONIC BONDS Let’s Practice!!! Write chemical formulas for:

1.) K and N2.) Ca and F3.) Li and Cl4.) Mg and Si5.) Al and O

1.) K3N

2.) CaF2

3.) LiCl4.) Mg2Si

5.) Al2O3

IONIC BONDSHow did you do??? 6.) Ca and Cl7.) K and P8.) Mg and Cl9.) Li and P10.) K and O

6.) CaCl27.) K3P

8.) MgCl29.) Li3P

10.) K2O

MetalMetal NonmetaNonmetall

ChemicaChemical l

FormulaFormula

Compound Compound NameName

Chemical Formulas Rb and Cl Na and S Li and P1. Hints: The metal comes first, the non-metal comes

secondChange the end of the name of the second element to

“ide”Copy down this table for your answers.

2. If you mix Calcium Chloride (CaCl2. If you mix Calcium Chloride (CaCl22) into a glass of ) into a glass of water until it dissolves, what is the chemical formula?water until it dissolves, what is the chemical formula?

MetalMetal NonmetaNonmetall

ChemicaChemical l

FormulaFormula

Compound Compound NameName

Chemical Formulas Rb and Cl Na and S Li and P1. Hints: The metal comes first, the non-metal comes secondChange the end of the name of the second element to “ide”

2. If you mix Calcium Chloride (CaCl2. If you mix Calcium Chloride (CaCl22) into ) into a glass of water until it dissolves, what is a glass of water until it dissolves, what is the chemical formula?the chemical formula?

RbSodium Sulfide

Cl

Na S

Li P

RbCl

Na2S

Li3P

Rubidium Chloride

Lithium Phosphide

CaCl2 (aq)

+1 -1

+1 -2

+1 -3

Ionic Bonds Warm-up

Write the chemical formulas for the compounds

formed when these ions bond:11.) Al & S

12.) Rb & O

13.) Be & F

14.) Al & Cl

15.) Ca & N

16.) Ga & Se

13.) BeF2

11.) Al2S3

12.) Rb2O

14.) AlCl3

15.) Ca3N2

16.) Ga2Se3

Questions Without using your notes, answer the following

questions. Write the questions!1. What is a compound?

Two or more DIFFERENT atoms (elements) that are chemically bonded together because of a chemical reaction.

2. Which formula is a compound and why?C8H10N4O2 or F2

C8H10N4O2= compound3. What are the element(s) that make up each

chemical formula in question 2? How many are in each element?

8 Carbon, 10 Hydrogen, 4 Nitrogen, 2 Oxygen2 Fluorine

COVALENT BONDS• Form between two

non-metals

• They bond because the outer electron rings are not full so they share valence electrons!

• (The atoms are NOT stable.)

Properties of COVALENT BONDS

• Covalent compounds will have low melting and boiling points.

• These are usually weak bonds.

• Some examples are H2O (water/ wudder), and CO2 (Carbon Dioxide)

COVALENT BONDS• The reason H2O is covalent:

Remember H can be a metal or a non-metal!!! (See RFA 11)

Here H is behaving like a non-metal. Hydrogen is usually a non-metal!

Let’s Practice!Write the following compounds and

determine if they are Ionic or Covalent?

1.) NH3 7.) AlCl32.) NaCl 8.) P2O5

3.) CH4 9.) Li3P

4.) CO2 10.) BN

5.) CaCl2 11.) N2O

6.) KBr 12.) MgS

ANSWERS…1.) NH3 Covalent 2.) NaCl Ionic 3.) CH4 Covalent 4.) CO2 Covalent 5.) CaCl2 Ionic 6.) KBr Ionic

7.) AlCl3 Ionic

8.) P2O5 Covalent

9.) Li3P Ionic

10.) BN Covalent

11.) N2O Covalent

12.) MgS Ionic

Lewis Structures Electron Dot

Diagrams• We can show how the atoms

share or transfer electrons by drawing electron dot diagrams.

• You will only use the valence e- for dot diagrams.

Dot Diagrams

• Start the dot diagram by writing the atomic symbol for the atom.

Ex: Mg

The symbol has 4 sides…

Dot Diagrams

Mg

Each side can hold up to 2e-

You cannot pair the electrons until there is one on each side.

Dot Diagrams

Mg

Mg only has 2 valence e-.

So it’s dot diagram looks like this: Mg Let’s try… Si

how about… S

Dot Diagrams Practice!!! Draw the Dot Diagrams for:

1.) Cl

2.) Al

3.) Na

4.) Sn

5.) Ar

Dot Diagrams

Now we can put individual diagrams together to show whether atoms transfer or share their valence e-!!!

Who donates their electrons, metals or non-metals?

Metals always donate their electrons!

Dot Diagrams for Ionic Bonds

In an Ionic Bond, atoms are transferring their valence e- …To show this “transferring” , we draw arrows between the Atomic Symbols to represent the transferring of e-.We can show this w/ dot diagrams.

For Ex: (Li + Cl = LiCl) Cl Li

Dot Diagram Practice for Ionic Bonds

1. BeO2. NaCl3. MgS4. CaCl2

5. LiP6. AlCl


2. NaCl

3. MgS


5. LiP

6. AlCl

Dot Diagrams for Covalent Bonds

In a Covalent Bond, atoms are sharing their valence e- …

To show this “sharing”, we draw a BAR between the Atomic Symbols to represent the sharing of e-.

One bar = 2 e-.

For Ex: H2O

Dot Diagrams for Covalent Bonds

One bar = 2 e-.

For Ex: H2O (draw out the individual dot diagrams first.)

H O H

***H’s ALWAYS have to go on the ENDS.

Dot Diagram Practice for Covalent Bonds

1.CO2.CH3.SO4.NH5.SiO6.CF

Bonding Dot Diagram Steps

1.) Identify the type of bond you have. (Covalent or Ionic)

2.) Separate the individual elements and put them in a line. Put the atomic symbol w/ least amount of valance electrons in CENTER!!!

3.) Except the Hydrogen’s!!!! Remember H’s have to be on ENDS!!!

4.) Draw the “dots” for each atomic symbol.

Bonding Dot Diagram Steps

5.) Show either the transferring or sharing of e- with arrows or bars.

6.) If sharing (covalent bonds)…connect the “lonely” dots between DIFFERENT symbols!!!

7.) Count the e- around each atomic symbol to make sure there are 8!!! (ONLY 2 for H!)

1234 HONCBased on your prior knowledge of atoms and their valance electrons, what in the world does 1234 HONC mean?

Hydrogen, Oxygen, Nitrogen, CarbonBased on their valance electrons, how many atoms can bond to each of them?

1 2 3 4H O N C

H= can form one bond.O= can form two bonds.N= can form three bonds.C= can form four bonds.**This works for COVALENT bonds only**

Dot Diagram Practice

1.) NF32.) Sr3N2

Dot Diagram Practice1.) NF3

2.) Sr3N2

3.) Rb2O

4.) CH3Cl

5.) Al2S3

6.) Na3N


3.) Rb2O 4.) CH3Cl


5.) Al2S3 6.) Na3N


7.) CH3Br

8.) NH2Cl

9.) PCl3

10.) CH4

11.) Br2O

12. IBr


7.) CH3Br 8.) NH2Cl


9.) PCl3 10.) CH4


11.) Br2O 12. IBr

Quick QuizCovalent bonds form

because…A. Share valence electrons B. Like charges attractC. They gain neutrons D. Opposite charges attractE. They share protons

The compound C6H12O6

hasA. Ionic bondsB. Covalent bondsC. Nuclear bondsD. Metallic bondsE. Hydrogen

bonds

Covalent bonds mostly occur with atoms on the right side of

the periodic table.

A. TrueB. False

Ionic bonds have…A. Strong bonds, low

boiling and melting points

B. Weak bonds, low boiling and melting points

C. Strong bonds, high boiling and melting points

D. Weak bonds, low boiling points and high melting points

Ionic bonds are formed because

A. Opposite charges attractB. Share valence electronsC. Electrons are transferredD. Protons are transferredE. Both A & CF. Both C & D

Which compound has ionic bonds? *

A. CO2

B. CuSO4

C. O2

D. CH4

The Law of Conservation

of MassThe Law of Conservation of Mass states that in a chemical reaction, mass cannot be created or destroyed, but it can change forms!

So this means that the mass before the reaction has to be the same as the mass after the reaction.

6CO2 + 6H2O C6H12O6 + 6O2

Does this equation go against the Law of

Conservation of Mass? (count the atoms of each element)Photosynthe

sis

Reactants

Products

Chemical

Reaction

Balancing EquationsDue to the Law of Conservation of Mass each type of element needs the same amount before the reaction and after the reaction.

“reactant(s) = product(s)”

But, you can’t change the elements that participate in the reaction, so you must write a number in front of (to the left of) each material in the reaction to make sure every type of element has the same number on each side of the reaction.

How molecules are symbolized

Cl2 2Cl 2Cl2

Cl Cl ClCl Cl Cl ClCl

How is the middle picture different from the other two?

Balancing EquationsCaCl2 Subscript

The little two tells you that there are 2 Cl. It only applies to the Cl.

But… 2CaCl2

When you have a Coefficient 2CaCl2

CaCl2

+CaCl2

The 2 tells you that there are 2Ca and 4ClIt applies to everything behind it in the compound.

You will NEVER add a subscript only Coefficients!

Understanding Chemical

CompoundsHow many atoms are in each chemical compound?

C6H12O6

2H2O2

6CuNO3

6 C4 H

4 O6 O12 H

6 Cu 6 N 18 O

6CO2 + 6H2O C6H12O6 + 6O2

Now, Does this equation go against the Law of

Conservation of Mass?

6C

12 O

12 H

6 O

6C

12 H

6 O

12 OThis does not violate the Law of Conservation of Mass

Understanding Chemical Compounds

How many atoms are in each chemical compound?

C20H30O2

3C6H12S2

2K3PO4

2C3H7NO

2

2Al2S3

4KClO3

20 C

4 O2 N14 H6 C

6 S4 Al

12 O4 Cl4 K

6 K

2 O30 H

2 P

18 C 6 S36 H

8 O

Explain what are three differences between a Covalent bond and an Ionic

Bond?Covalent Bonds1. Share valence electrons

2. Non-metal and Non-metal

3. Weak bonds4. Low Boiling Pts. and

Melting pts.

Ionic Bonds1. Opposite charges attract

2. Metal and Non-metal3. Strong bonds

4. High Boiling Pts. and Melting pts.

Try this without using your notes

RFA 23CaCl2

C6H12O6

H2SO4

NH4Cl

2NH4NO3

3BaTiO3

Ca 2 Cl

6 C 12 H 6 O

2 H S 4 O

N 4 H Cl

6 O2 N8 H2 N

9 03 Ti3 Ba

4NaHCO3

8Bi2Te3

5CaCrO4

3SiH2Cl2

6Fe2O3

5NaOH

16 Bi

20 0

24 Te

5 Cr5 Ca

6 Cl6 H3 Si

18 O12 Fe

5 H5 O5 Na

4 Na 12 O4 C4 H

Warm up ReviewWhat is the chemical formula for each one and WHY?

1.)

2.)

3.)

1.) 3Na2 (3 pairs chemically bonded)

2.) Na2 (1 pair chemically bonded)

3.) 2Na (not chemically bonded)

NaNa NaNa

Na Na

NaNa

Na Na

Balancing EquationsWhat’s the difference between…A2 + B2 and A2B2 ?

A2 + B2 = Not chemically bonded, so its not a compound! These are elements.

A2B2 = This is chemically bonded because it is a compound.

Balancing EquationsLet’s look at an example:

Element Mg will bond with element O in the chemical reaction below:

Mg + O2 MgO

Are there the same amount of O’s on the left as there are on the right???

NO!!! We must balance this equation!!!

O Mg O+ Mg O

Balancing EquationsHow can we make there be the same # of each element on both sides???

Mg + O2 MgO

“reactants = product”

By putting a coefficient in FRONT... Mg + O2 2MgO

You multiply all of the elements in the compound by the coefficient in front.

Is it balanced yet???

NO!

O Mg O+ Mg O

Balancing EquationsWhere else could we put a coefficient to balance it?

Mg + O2 2MgO “reactants = product”

We need to add a coefficient in the front on the other side…

2Mg + O2 2MgO“reactants = product”

There are 2Mg’s and 2 O’s on the left AND there are 2Mg’s and 2 O’s on the right…NOW it’s BALANCED!!!

Balancing Equations 2Mg + O2 2MgO

I only added Coefficients!

So let’s practice with some real problems to see how you do!

Reactants =

product

Balancing EquationsLet’s practice…

1.) Al + Br2 AlBr3

2.) H2 + O2 H2O

3.) Na + Cl2 NaCl

3.) 2Na + Cl2 2NaCl

4.) Fe + O2 Fe2O3

4.) 4Fe + 3O2 2Fe2O3

5.) P4 + O2 P2O5

5.) P4 + 5O2 2P2O5

Balancing Equations…

6.) N2 + H2 NH3

7.) Mg + O2 MgO

8.) H2 + Cl2 HCl

9.) Ag + S Ag2S

10.) S + O2 SO4

Balancing Equations…

Lets see how you did!6.) N2 + 3H2 2NH3

6a.) 2N2 + 6H2 4NH3 Is this balanced?

7.) 2Mg + O2 2MgO

8.) H2 + Cl2 2HCl

9.) 2Ag + S Ag2S

10.) S + 2O2 SO4

Metallic Bonds• Form between 2 metal atoms. (metal and

metal) • The atoms are unstable – they do not have

full electron rings.• Bond by sharing very loosely held valence

electrons with each other. (The electrons “flow” between the atoms.)

• Metallic bonds are NOT the strongest bonds though…

• Ionic Bonds are the strongest bonds!

Properties of Metallic Bonds

• Metallic compounds are highly conductive. (They conduct heat & electricity very easily!!!)

• They also have metallic luster (shine)• They are malleable (able to be

hammered into thin sheets.)• They are ductile (can be rolled into

wires.)• Examples: CuZn, AlSb, GaSb, LaMg

What makes it easier for some atoms to bond better than other

atoms?When you think about atoms bonding,

what do atoms need to gain or lose?VALENCE ELECTRONS!!!

N-3 Li+1

Which atom will bond the easiest? Li+1 Why?

The LESS electrons an atom needs to gain or lose to have a full outer ring, the EASIER it is for that atom to bond!!!

Which groups (1-18) on the periodic table, will bond the

easiest?

Which groups on the periodic table will share or transfer electrons the

easiest? (i.e. be most likely to form bonds?)

ANSWER: Groups 1 and 17 b/c group 1 only needs to get rid of 1e- and group 17 only needs to gain 1e-.

Question…

Is an element in Group 13 more likely to bond than an element in Group 16? EXPLAIN…

ANSWER: No, b/c the element in Group 16 only needs to gain 2e-, but the element in Group 13 needs to lose 3e-.

have you ever heard the word bonding before?

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