Ionization Energies

Revised 11/20/1105/18/12

Mike JonesPisgah High School

Canton NC

Ionization energy

The energy needed to remove an electron completely from at atom.

Depends upon ….

The attraction between the positively charged nucleus and the negatively charged electron.

The repulsion between the negatively charged electrons.

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

H

He

Li

Be B

C

N O

F

Ne

Na

Mg Al

Si

P S

Cl

Ar

K

Ca

0

500

1,000

1,500

2,000

2,500

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

Ar

K

Ca Sc Ti V Cr

Mn Fe Co Ni Cu

Zn

Ga

Ge

As Se

Br

Kr

Rb

Sr

0

200

400

600

800

1,000

1,200

1,400

1,600

Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

2

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82 8

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82 8

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82 8 18

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82 8 18

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82 8 18 18

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82 8 18 18

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

+

82 8 18 18

28

8

18

18

32

H

He

Li

Be B

C

N O

F

Ne

Na

Mg Al

Si

P S

Cl

Ar

K

Ca

0

500

1,000

1,500

2,000

2,500

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

Eight electrons are filling the second energy level.Why does the ionization energy increase along a period?

H

He

Li

Be B

C

N O

F

Ne

Na

Mg Al

Si

P S

Cl

Ar

K

Ca

0

500

1,000

1,500

2,000

2,500

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

Why are there “blips” in the ionization energies?

H

He

Li

Be B

C

N O

F

Ne

Na

Mg Al

Si

P S

Cl

Ar

K

Ca

0

500

1,000

1,500

2,000

2,500

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

The second energy level must be subdivided into two sublevels each with a different energy.

The fifth electron for boron must be in a higher energy level because it takes less additional energy to remove it.

H

He

Li

Be B

C

N O

F

Ne

Na

Mg Al

Si

P S

Cl

Ar

K

Ca

0

500

1,000

1,500

2,000

2,500

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

Electrons in the lower sublevel

Electrons in the higher sublevel

The second energy level must be subdivided into two sublevels each with a different energy.

The fifth electron for boron must be in a higher energy level because it takes less additional energy to remove it.

H

He

Li

Be B

C

N O

F

Ne

Na

Mg Al

Si

P S

Cl

Ar

K

Ca

0

500

1,000

1,500

2,000

2,500

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca

The same is true for the third energy level.

Electrons in the lower sublevel

Electrons in the higher sublevel

There are many limitations of the Bohr model, including the fact that the calculations work only for hydrogen.

But there is one overriding reason why the Bohr model is so important to our study of the atom and the arrangement of electrons.

The Bohr model tells us that electrons are located only in certain, discrete energy levels and that they can only change from one energy level to another by gaining or losing energy.

1

2

3

4

The Bohr model has a few discrete energy levels.

An “excited electron” is located in one of these energy levels

A ground-state electron is located in the lowest energy level.

n 2n2

1 2

2 8

3 18

4 32

5 50

The number of electrons in the nth energy level is given by 2n2.

The Bohr model showed only 8 electrons in the third energy level. Where are the other ten electrons?

1

2

3

4

The Quantum mechanical model has more energy levels available to electrons

Except for the first energy level, each energy level in the Bohr model is “subdivided” into two or more “sublevels.”

n 2n2

1 2

2 8

3 18

4 32

5 50

n is the “principle quantum number, one of 4 numbers that uniquiely describe each electron in an atom

n 2n2

1 2

2 8

3 18

4 32

5 50

In multi-electron atoms the original Bohr energy levels are split into sublevels.

1

2

3

4

n 2n2

1 2

2 8

3 18

4 32

5 50

In multi-electron atoms the original Bohr energy levels are split into sublevels.

1

2

3

4

n 2n2

1 2

2 8

3 18

4 32

5 50

In multi-electron atoms the original Bohr energy levels are split into sublevels.

1

2

3

4

Overlap between energy sublevels.

n 2n2

1 2

2 8

3 18

4 32

5 50

In multi-electron atoms the original Bohr energy levels are split into sublevels.

1

2

3

4

1s

2s

2p

3s

4s

3p

4p

3d

4d4f The letters s,

p, d and f are used to label the sublevels.

s = sharp

p = principle

d = diffused

f = fundamental

n 2n2

1 2

2 8

3 18

4 32

5 50

In multi-electron atoms the original Bohr energy levels are split into sublevels.

1

2

3

4

1s

2s

2p

3s

4s

3p

4p

3d

4d4f

sublevel number of electrons

s 2

p 6

d 10

f 142

8

18

32

The letters s, p, d and f are used to label the sublevels.

Periodic table - Sublevels

s pd

f2 610

14How many electrons go in each region?

Since we can’t see atoms or the electrons we have no idea what they actually look like. Yet we need a way to represent the organization of electrons in an atom.

Much like technicians use a schematic diagram to represent the components in an electronic circuit, chemists use the electron energy diagram to represent electrons in an atom.

Much like technicians use a schematic diagram to represent the components in an electronic circuit, chemists use the electron energy diagram to represent electrons in an atom.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p7s

5f6d

7p

E n

e r

g

y

Electron Energy Diagram

n 2n2

1 2

2 8

3 18

4 32

5 50

s 2

p 6

d 10

f 14

The electron energy diagram is a schematic diagram representing the arrangement of electrons in an atom. It consists of lines representing the orbitals in the various energy sublevels.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p7s

5f6d

7p

E n

e r

g

y

Electron Energy Diagram

n 2n2

1 2

2 8

3 18

4 32

5 50

s 2

p 6

d 10

f 14Each of the lines represents an “orbital” where up to two electrons can be located.

An orbital is a “region in space” within an atom where up to two electrons can be located.

An s-orbital is spherical. Two electrons.

The p-orbitals are “dumbell” shaped. Each orbital contains two electrons, for a total of six

The Shrodinger wave equation predicts the shape of the orbitals.

The five d-orbitals are shaped like this. Each orbital can contain two electrons, for a total of 10 electrons. The transition metals are filling

the d-orbitals.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

E n

e r

g y

Electron Energy Diagram for Arsenic

Electrons with opposite spin are represented by up and down arrows.

Each horizontal line represents an orbital, a region which can be occupied by up to two electrons.

The electron energy diagram represents the arrangement of the electrons in their respective energy levels and sublevels.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p7s

5f6d

7p

E n

e r

g

y

Electron Energy Diagram

1s

E n

e r

g

y

Electron Energy Diagram

1s

2s2p

E n

e r

g

y

Electron Energy Diagram

The second energy splits into two sublevels called “s” and “p”. An s-sublevel holds two electons. A p-sublevel holds up to six electrons in three orbitals.

1s

2s2p

3s3p

3d

E n

e r

g

y

Electron Energy Diagram

The third energy splits into three sublevels, the “s”, the “p”, and the “d”. The d-sublevel holds up to ten electrons in five orbitals.

1s

2s2p

3s

4s3p

4p

3d

4d

4f

E n

e r

g

y

Electron Energy Diagram

The fourth energy splits into four sublevels, the “s”, the “p”, the “d”, and the “f ”. The f-sublevel holds up to 14 electrons in seven orbitals.

Notice that the 4s sublevel is lower in energy than the 3d sublevel.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

4f5d

5fE

n e

r g

y

Electron Energy Diagram

Notice the overlap again in the 5s and 4d, and the location of the 4f sublevel.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p

5f6d

E n

e r

g

y

Electron Energy Diagram

The 6s-sublevel is lower in energy than the 4f sublevel.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p7s

5f6d

7p

E n

e r

g

y

Electron Energy Diagram

The 7s-sublevel is lower in energy than the 5f sublevel.

The energy sublevels are filled in order from lowest energy to highest energy.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p7s

5f6d

7p

E n

e r

g

y

Electron Energy Diagram

Order in which the energy sublevels are filled.

Periodic table - Sublevels

s pd

f

Order in which the energy sublevels are filled.

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p7s

5f6d

7p

E n

e r

g

y

Electron Energy Diagram

The order in which the orbitals are filled can also be predicted from the graph of ionization energy.

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s

H

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s

He

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s

Li

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s

Be

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p

B

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p

C

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p

N

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p

O

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p

F

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p

Ne

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s

Na

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s

Mg

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p

Al

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p

Si

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p

P

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p

S

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p

Cl

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p

Ar

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s

K

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s

Ca

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Sc

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Ti

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

V

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Cr

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Mn

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Fe

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Co

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Ni

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Cu

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d

Zn

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p

Ga

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p

Ge

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p

As

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p

Se

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p

Br

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p

Kr

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s

Rb

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s

Sr

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d

Y

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d

Tc

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d

Cd

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p

In

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p

Sb

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p

Xe

H

He

Li

Ne

Na

Ar

K

Kr

Rb

Xe

Cs

0

500

1,000

1,500

2,000

2,500

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p

Cs

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

E n

e r

g y

Electron Energy Diagram for Arsenic

We can represent the arrangement of electrons more simply by using the “electron configuration.”

1s2, 2s2 2p6, 3s2 3p6, 4s2 4p3

1s2, 2s2 2p6, 3s2 3p6, 4s2 4p3

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

E n

e r

g y

Electron Energy Diagram for Arsenic

We can simplify the “electron configuration” even more by using the “inert gas core” to represent the electrons which do not take part in chemical reactions.

Ar 4s2 4p3

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

E n

e r

g y

Electron Energy Diagram for Arsenic

We can simplify the “electron configuration” even more by using the “inert gas core” to represent the electrons which do not take part in chemical reactions.

Ar 4s2 4p3

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

E n

e r

g y

Electron Energy Diagram for Arsenic

Write the electron configuration using the inert gas core for the following elements:1. Al 4. P2. V 5. Sn3. Br 6. Bi

Write the electron configuration using the inert gas core for the following elements:

1. Al 4. P2. V 5. Sn3. Br 6. Bi

1. [Ne] 3s2 3p1

2. [Ar] 4s2, 3d3

3. [Ar] 4s2, 3d10, 4p5

4. [Ne] 3s2, 3p3

5. [Kr] 5s2, 4d10, 5p2

6. [Xe] 6s2, 4f14, 5d10, 6p3

How many valence electrons does each element have?

Valence electrons are the outer-most electrons which are involved in bonding.

1. [Ne] 3s2 3p1

2. [Ar] 4s2, 3d3

3. [Ar] 4s2, 3d10, 4p5

4. [Ne] 3s2, 3p3

5. [Kr] 5s2, 4d10, 5p2

6. [Xe] 6s2, 4f14, 5d10, 6p3

1. Al 32. V 5 3. Br 74. P 35. Sn 46. Bi 5

Look at the Roman numeral at the top of the column for each element.

The valence electrons have the highest principal quantum number.

Mike JonesPisgah High SchoolCanton NCmjones@haywood.k12.nc.us

+

1s

2s2p

3s

4s3p

4p

3d

4d5s

5p

6s 4f5d

6p7s

5f6d

7p

E n

e r

g

y

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