electrons in atoms. energy level (shell) sublevelsorbitalsnumber of electrons 1s1 s orbital2 2s, p1...

Electrons in Atoms

Energy level (shell)

Sublevels Orbitals Number of electrons

1 s 1 s orbital 2

2 s, p 1 s orbital

3 p orbitals

8

3 s, p, d 1 s orbital

3 p orbitals

5 d orbitals

18

4 s, p, d, f 1 s orbital

3 p orbitals

5 d orbitals

7 f orbitals

32

As orbitals:

Hold 2 electrons(outer orbitals ofGroups 1 and 2)

Bp orbitals:

Each of 3 pairs oflobes holds 2 electrons

= 6 electrons(outer orbitals of Groups 13 to 18)

Cd orbitals:

Each of 5 sets oflobes holds 2 electrons

= 10 electrons(found in elements

with atomic no. of 21and higher)

Kelter, Carr, Scott, , Chemistry: A World of Choices 1999, page 82

• Valence electrons: Electrons in the outer most shell.

Copyright © 2010 Ryan P. Murphy

1 2 1 4 5 1

Total Electrons

DOT & CROSS DIAGRAMSDOT & CROSS DIAGRAMS

With Dot & Cross diagrams elements and

compounds are represented by Dots or Crosses to

show electrons, and circles to show the shells. For

example;

Nitrogen N XX X

X

XX

X

N7

14

DOT & CROSS DIAGRAMSDOT & CROSS DIAGRAMS

Draw the Dot & Cross diagrams for the following elements;

O P8 15

16 31a) b)

O

X

XX

X

X

X

X

X

Cl

X

X

X

X

X

XX

X

X

X

X

X

X

X

X

• How many electrons are in the first three energy levels?

Copyright © 2010 Ryan P. MurphyCopyright © 2010 Ryan P. MurphyCopyright © 2010 Ryan P. Murphy

• Pauli Exclusion Principle

• Each orbital can hold TWO electrons with opposite spins.

• Aufbau Principle

• Electrons fill the lowest energy orbitals first.

• Where would you

want to sit at a

baseball game or

concert

RIGHTWRONG

• Hund’s Rule• Within a sublevel, place one e- per orbital before pairing

them.

• “Empty Bus Seat Rule”

© 1998 by Harcourt Brace & Company

sp

d (n-1)

f (n-2)

1234567

67

• Hydrogen is an odd ball. • It’s grouped with the alkali metals because it has a similar

outer shell electron configuration as they do. It’s not metal? Also needs one electron.

Copyright © 2010 Ryan P. Murphy

• Period # (Row)• indicates the highest energy level (subtract for d & f)

• Group # (Column)• Indicates the total # of valence e-

• Column within sublevel block• # of e- in sublevel

Mendeleev

The periodic table arranges all the elements in groups according to their properties.

Horizontal rows are called PERIODS

Vertical columns are called GROUPS

H He

Li Be B C N O F Ne

NaMg

Al Si P S Cl Ar

K Ca Fe NiCu

Zn Br Kr

Ag I Xe

PtAu

Hg

Elements in the same group have the same number of electrons in the outer shell (this

correspond to their group number)

E.g. all group 1 metals have __ electron in their outer shell

These elements have __ electrons in their outer shell

These elements have __ electrons in their outer shells

s-block

1st Period

1s11st column of s-block

• Example - Hydrogen

O

8e-

• Orbital Diagram

Electron Configuration

1s2 2s2 2p4

1s 2s 2p

Shorthand Configuration

S 16e-

Valence Electrons

Core Electrons

S 16e- [Ne] 3s2 3p4

1s2 2s2 2p6 3s2 3p4

• Longhand Configuration

1

2

3

4

5

6

7

• Shorthand Configuration• Core e-: Go up one row and over to the Noble Gas.• Valence e-: On the next row, fill in the # of e- in each

sublevel.

neon's electron configuration (1s22s22p6)

[Ne] 3s1

third energy level

one electron in the s orbital

orbital shape

Na = [1s22s22p6] 3s1 electron configuration

AA

BB

CC

DD

[Ar] 4s2 3d10 4p2

• Example - Germanium

• Full energy level

1

2

3

4 5

6

7

Full sublevel (s, p, d, f)Half-full sublevel

• An ATOM with a charge• Different # of electrons• Atomic # = Proton #• Atomic mass = Protons + Neutrons• A cation - positive ion

• formed when an atom loses electrons.• Example: Na+

• An anion - negative ion• is formed when an atom gains electrons

• Example: Cl-

• Ion Formation• Atoms gain or lose electrons to become more stable.

O2- 10e- [He] 2s2 2p6

• Ion Electron Configuration• Write the e- config for the closest Noble Gas

• EX: Oxygen ion O2- Ne

[Ar] 4s2

Electron configurationElement symbol

[Ar] 4s2 3d3

[Rn] 7s2 4f14 5d4

[He] 2s2 2p5

[Kr] 5s2 4d9

[Kr] 5s2 4d10 5p5

[Kr] 5s2 4d10 5p6

[He] 2s22p63s23p64s23d5

Ca

V

Sg

F

Ag

I

Xe

Fe

Energy Level Diagram

Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model


CLICK ON ELEMENT TO FILL IN CHARTS

N

C = 1s22s22p2

Carbon

H He Li C N Al Ar F Fe La


Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS



N

N = 1s22s22p3

Bohr Model

Nitrogen

Hund’s Rule “maximum

number of unpaired

orbitals”.



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

F = 1s22s22p5

Fluorine



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS

Bohr Model



N

Al = 1s22s22p63s23p1

Aluminum



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS



N

Ar = 1s22s22p63s23p6

Bohr Model

Argon



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS


Fe = 1s22s22p63s23p64s23d6

N


Bohr Model

Iron



Arb

itrar

y E

nerg

y S

cale

1s

2s 2p

3s 3p

4s 4p 3d

5s 5p 4d

6s 6p 5d 4f

NUCLEUS


La = 1s22s22p63s23p64s23d10

4s23d104p65s24d105p66s25d1

N


Bohr Model

Lanthanum


electrons in atoms. energy level (shell) sublevelsorbitalsnumber of electrons 1s1 s orbital2 2s, p1...

Documents

valence electrons

energy levels

lowest energy orbitals

valence ecolumn

highest energy level

bp orbitals

cd orbitals

d f group