PERIODIC TRENDS IN IONIZATION ENERGY

In this activity, you will prepare a graph of ionization energy as a function of atomic number.  Using this graph, you will investigate the trends in ionization energy within a group and a period of the Periodic Table.

PROCEDURE:
1.  Label the horizontal axis atomic number and the vertical axis ionization energy.  Set up appropriate scales for the data provided below.  (Click here to learn how to set up appropriate scales for your data.)  Plot the data and join the points with a solid line.  Do not label each data point.

1

H

1310

 

15

P

1060

 

29

Cu

745

 

42

Mo

693

2

He

2370

 

16

S

999

 

30

Zn

906

 

43

Tc

-

3

Li

520

 

17

Cl

1260

 

31

Ga

579

 

44

Ru

724

4

Be

899

 

18

Ar

1520

 

32

Ge

785

 

45

Rh

743

5

B

800

 

19

K

419

 

33

As

965

 

46

Pd

804

6

C

1090

 

20

Ca

590

 

34

Se

941

 

47

Ag

731

7

N

1400

 

21

Sc

633

 

35

Br

1140

 

48

Cd

868

8

O

1310

 

22

Ti

659

 

36

Kr

1350

 

49

In

558

9

F

1680

 

23

V

650

 

37

Rb

403

 

50

Sn

708

10

Ne

2080

 

24

Cr

652

 

38

Sr

549

 

51

Sb

834

11

Na

496

 

25

Mn

717

 

39

Y

637

 

52

Te

869

12

Mg

738

 

26

Fe

762

 

40

Zr

671

 

53

I

1007

13

Al

577

 

27

Co

758

 

41

Nb

653

 

54

Xe

1170

14

Si

786

 

28

Ni

737

 

 

 

 

 

 

 

 

Link to paper to graph this data

2.  Divide the graph into several sections by drawing vertical lines through the points that represent the noble gases.

ANALYSIS:
1.  Create two lists:
    (A) the symbols of the elements with the lowest ionization energy in each section
    (B) the symbols of the elements with the highest ionization energy in each section

CONCLUSIONS:

Within a period, as atomic number increases, ionization energy generally ____________________ because...

 

Exceptions to this trend occur at groups ____ and ____.  This is probably due to ...

 

Within a group, as atomic number increases, ionization energy ____________________ because...

 

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