Bonding - Atoms interact (with their electrons) to form compounds. Sodium Chlorine.

Bonding - Atoms interact (with their electrons) to form compounds.

Sodium

Chlorine

2Three Kinds of Bonds:

IonicIonic

CovalentCovalent

MetallicMetallic

Metal gives up electrons to make opposites attract.

The sharing of electrons creates a strong bond.

All electrons are shared in a “sea of electrons.”

Metal (+) Nonmetal (-)

Nonmetal Nonmetal

Metal Metal

electrons

Metal

Metal

Metal

3

Independent Practice

Fill in the the blanksC - CovalentM - Metallic

I - Ionic

4

To understand how bonding works, we need to understand electrons.

ProtonProton

ElectronElectron

NeutronNeutron + +

Positive Charge

No Charge

Negative Charge

5

Valence ElectronsValence ElectronsThe electrons on the outer energy level of an atom

How many valence electrons do each of these have?

5

2

31

4

6

1

5

6

3

Li6.941

11

Na22.990

12

Mg24.305

19

K39.098

20

Ca40.08

16

S32.066

17

Cl35.453

18

Ar39.948

10

Ne1.0079

9

F18.998

13

Al26.982

14

Si28.086

15

P30.974

5

B10.811

6

C12.011

7

N14.007

8

O15.999

1

H1.0079

4

Be9.012

2

He4.003

2

8

8

Do you remember what the atomic number

represents?It is the number of protons &

electrons.

71

H1.0079

2

He4.003

Energy Level 12 electrons fit

Fill in the periodic table on your paper.

How many valence electrons does hydrogen have?

How many valence electrons does helium have?

8

3

Li6.941

10

Ne1.0079

9

F18.998

5

B10.811

6

C12.011

7

N14.007

8

O15.999

4

Be9.012

Energy Level 28 electrons fit:


How many valence electrons do each of the elements above have?

9

11

Na22.990

12

Mg24.305

16

S32.066

17

Cl35.453

18

Ar39.948

13

Al26.982

14

Si28.086

15

P30.974

Energy Level 38 electrons fit


How many valence electrons do each of the elements above have?

10

Look at the periodic table. Do you notice a pattern?

What is it?

11

You should have noticed that each column has the same number of

valence electronsvalence electrons.This is true all the way down

the periodic table:1

2 3 4 5 6 7

8

12

But there is something you need to know about electrons and the energy levels where they live.

Some are happier than others.Some are happier than others.

You see, energy levels like to be FULL.You see, energy levels like to be FULL.

10

Ne1.0079

18

Ar39.948

2

He4.003

Which other atoms are FULL?

These are “HAPPY” atoms.These are “HAPPY” atoms.

13Everyone wants to be happy--Everyone wants to be happy--

so, all atoms try to get happy.so, all atoms try to get happy.

But alas, they cannot do it alone. They But alas, they cannot do it alone. They must find other atom friends to make must find other atom friends to make them happy.them happy.

• Someone that understands you.Someone that understands you.• One who is willing to give you what you need most -- One who is willing to give you what you need most --

a part of himself.a part of himself.

But the right kind of friend is hard to find -- if you But the right kind of friend is hard to find -- if you know what I mean.know what I mean.

14More on electrons:More on electrons:

Atoms get happy (stable) by filling up their outer shell of electrons.

Atoms with Atoms with 4 or more4 or more valence electrons valence electrons will not give them up!will not give them up!

No, and don’t ask again!

Yes, is there anything else?

Atoms with less than 4 valence electronsAtoms with less than 4 valence electrons are very generous. are very generous.

Which columns on the periodic table will NOT give away electrons?

Which columns on the periodic tablewill give away electrons?

friend in

need

Generous Friend

15

However this affects their charge…Remember normally:

# of Protons (+) = Electrons (-)

If the the blue atom gives up an electron, it If the the blue atom gives up an electron, it becomes (+). becomes (+).

If the yellow atom gives up an electron, it becomes If the yellow atom gives up an electron, it becomes (-). (-).

Even MORE about electrons:Even MORE about electrons:

Have the same

Lose -e makes +

Gain -e makes -

Generous friend helps

a friend in need.

16

Because of this, we assign a group of Because of this, we assign a group of elements elements

an an oxidation number.oxidation number. Compare this number to the Compare this number to the valence valence

electronselectrons. . 1+

2+ 3+ 4 3- 2- 1-

01

2 3 4 5 6 7

8

Write the oxidation numbersWrite the oxidation numberson your periodic table.on your periodic table.

H He

Be B C N O F

17


Fill in the the chart on your paper.

18

BondingBondingAn atom’s outer electron energy

level is filled by either exchanging or sharing electrons.

NaClNaClNHNH33

Na ClNa ClN H H H

N H H H

N HH

H

ClNa

Sodium

Chlorine

Electrons either taken or given away

++ Opposites attract

Ionic BondsMetal to Nonmetal

19

20

Sodium Chlorine

SodiumSodium ChlorideChloride

Sodium is happy at energy level 2.Sodium is happy at energy level 2.Chlorine is happy at energy level 3.Chlorine is happy at energy level 3.

Sodium gives Chlorine 1 electron.

NaClNaCl

ClNa

Ionic BondsMetal to Nonmetal

21

NNHH3 3 AmmoniaAmmonia

N HH

H

Covalentnon-metal + nonmetal

HydrogenHydrogen

HydrogenHydrogen

HydrogenHydrogen

NitrogenNitrogen

Energy le

vel HAPPY

Energy le

vel HAPPY

or sta

ble...

or sta

ble...

Electrons are shared.

22

Metallic

-e -e

-e-e-e

-e -e -e

-e

Ag+ Ag+

Ag+

Ag+

Ag+ Ag+

Ag+Ag+

Ag+-e-e

-e-e

Share in a sea of electronselectrons

met

al

met

al

met

al

23



241+

2+ 3+ 4 3- 2- 1-

0

Mg+2Cl-1

MgCl2

1 2

Oxidation Number Oxidation Number VariesVaries

Mg+2O-2

MgO2 2=

Fe+3 O-2

Fe2O3

2 3

When you combine atoms, you use the oxidation numbers to help you figure out the ratio.

Simply switch the oxidation number to get the correct subscript. Put the #s in lowest terms if

necessary.

25



26Polyatomic Compounds:Compounds that Act as a Unit

Mg+2 PO4-

3

Mg3(PO4)2

3 2

Li+2 SO4-

2

LiSO4

2 2

Fe+3 NO4-2

Fe2 (NO4)3

2 3

Charge Name Formula 1+ Ammonium NH4

+

1- Acetate C2H3O4-

1- Chlorate ClO3

1- Hydroxide OH-

1- Nitrate NO3-

2- Carbonate CO32-

2- Sulfate SO42-

3- Phosphate PO43-

Note the ( ) on multiple polyatomic ions.Note the ( ) on multiple polyatomic ions.

27



28Naming CompoundsNaming Compounds

Rules for naming binary (meaning 2 types of atoms) ionic compounds:

1. Write the name of the metal first.

Example: KBr

Potassium Potassium

2. Write the name of the nonmetal changing the ending to “ide.”

BromineBromineBromBromideide

29


Fill in the blanks.


Rules for naming binary ionic compounds:


Example: CuCl

Copper Copper


ChlorineChlorineChlorChlorideide

3. If the metal is a “transition metal,” the oxidation number varies. Therefore, to name the compound we must put the ionic charge in parentheses. For example:

(I)

because the oxidation of chlorine is 1.

(Binary means 2 types of atoms.)

31


Fill in the blanks.


Rules for naming polyatomic ionic compounds:


Example: K2 SO4

Potassium Potassium

2. Write the name of the polyatomic nonmetal from the chart.

SulfateSulfate


+

1- Acetate C2H3O4-

1- Chlorate ClO3

1- Hydroxide OH-

1- Nitrate NO3-

2- Carbonate CO32-

2- Sulfate SO42-

3- Phosphate PO43-

Polyatomic


Rules for naming polyatomic ionic compounds:

1. Use the chart above to name the metal.

Example: NH4Cl

AmmoniumAmmonium

Ionic


+

1- Acetate C2H3O4-

1- Chlorate ClO3

1- Hydroxide OH-

1- Nitrate NO3-

2- Carbonate CO32-

2- Sulfate SO42-

3- Phosphate PO43-

If the polyatomic ion is first, then:


ChlorChlorideide

34

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Bonding - Atoms interact (with their electrons) to form compounds. Sodium Chlorine.

Documents

electrons fit

sharing of electrons

sea of electrons

number of valence electrons

number of protons electrons

outer shell of electrons

periodic table

generous friend slide