e
A CUT-OUT CHART OF THE PERIODIC SYSTEM JENNIE E. CLAUSON Glendale High School, Glendale, California
Tms chart was constructed to make available for student use the three-dimensional idea incorporated in the space model of the periodic system made in 1951.1,2 To overcome the fragility and instability of the previous model, which had wooden balls on a wire spiral, it was reconstructed using colored discs for the elements on a cylinder of transparent cellulose acetate plastic. (See Figure 1.) The chart on the circular base is similar, except that the radii are numbered counterclockwise, so the elements read from left to right on the cylinder. The discs are of colored paper bearing the symbol of the element and its atomic number on both sides. Slightly larger discs of plastic cover the colored ones and are cemented to the inside of the cvlinder. The elements of the short series are arranged spirally around a small cylinder whose diameter is half that of the larger one. The elements of the long series are arranged spirally around the large cylinder, the elements of Group I above radii I and 1', etc. The lanthanides are in a loop on e sheet of plastic that stands on the diameter 111-111'. The actinides form a similar loop farther down. Staples hold the edges of the cylinders together and fasten the small one to the lame one on the Group 0 line. A '/,-inch fold on the sides of the vertical sheet makekes it possible to staple it to the walls of the large cylinder. The colors of the discs follow roughly those of the spectrum. The same color repeats for Groups I and It, for I1 and 11', etc. The lanthanides and the actinides have the same color as color as Group 111. The nentron is black and the inert gases of Group 0 are gray. J. E.. "A anace model of the ~eriodicsystem."
1 CLA~ON.
J.
CHEM. ED&., 29,250 (i952).
1 Copies of the chart may be obtained from Pioneer Printing Co., Glendale 5, California.
OCTOBER. 1954
551
Elzl
TO MAKE CYLINDRICAL CHART Cut d o n g dotted lines. Fold back Lonthanide Series. Fold Ga
~ l l ~ ~ H ~ ~ l ~ i ~ l ~ l ~ l - l 4.003
6.94
9.013
He
Li
Be
10.82
12.01
14.008
16
19.00
3 4 5 6 7 8 9 2 20.183 22.997 24.32 26.98 28.09 30.975 32.066 35.457
Ne Na Mg
10
!2_- E-
11 39.1
19.944
A1
Si
40.08
V
A
K
Ca
Sc
Ti
Kr
Rb
Sr
Y
% NG
37
38
131.3 132.91 137.36
Xe
Cs 55
54
CI
14_--lS-_16--E-111 IV v VI VII 52.01 54.93 47.90 50.95 44.96
22 21 19 20 18 87.63 88.92 85.48 83.80
s6
S
P
Ba
56
39
40
23
41
Cr
24 .95
MO 42
TC 43
RU 44
- - - -150.43--- - - - - - - - - - - - -11451
La
Ce
Pr
short rerier back so extension underlops left margin. Repeat with
:
long series to make large cylinder. Forten folded ends of Lan-
f
thanide and Actinide Serier to back o f Ill I. Color before cutting.
Co
'
58.69
Ni
I 63.54
11 I 65.38
IV I 111 69.72 32.60
V' 74.91
VII' VI' 78.96 79.916
Cu
Zn
Ga Ge
As
Se
Rh
45
Pd
Ag
46
- --
152.0-
47
Cd 48
In 49
Nd P m S m Eu G d :
64 63 58 59 60 61 62 174.99 173.04 169.4 167.2 164.94 162.46 159.2:
_
Rn 6
Fr 87
Ra 88
Ac 89
Sb
51
I
Te
52
53
' :
116
117
lanlhanide Strier
---------------------------231 238.07 12371 12421 12431 12431 :
227 232.12
12231 226.05
Sn
50
-156.9 - - -1
Lu Y b T m Er H o Dy Tb I1- --E- - bP - - - bS_ --F---6_6- - - -65- --:
222
Br
32 33 27 28 30 31 34 35 26 29 101.7 102.91 1991 106.7 107.880 112.41 114.76 118.70 121.76 127.61 126.91
138.92 140.13- 140.92-144.27 57
and Tb forword. Make similar folds for Actinide Series. Roll
I
7 V l l l 58.94 55.85
Mn F e
25
:
Th
90
Pa
91
U
92
Np P u A m C m :
93
94
95 96 12461 12451
Cf
Bk _1!?3_--102 --10_'_--E--E---98_---91_-..: I04
105
106
107
108
109
110
:'
Actinide Serier
: 111
112
113
114
115
A PERIODIC TABLE of the ELEMENTS rim2
thanides and the actinides were cut with a sharp knife or razor blade. These strips were folded back a t the left edge. The last two elements of the double strips were folded forward. Glue was placed on the right margin of the chart, which was then rolled to make a cylinder, lining up the left edge against Group VII'. Similarly, the short series were rolled into a small cylinder a t the top. These edges may be fastened with staples if preferred. Glue was placed on the back of the tab a t the end of the lanthanide strip to fasten it inside the cylinder in Group 0 uncolored line with Group 111'. The same was done with the Groups I and I' purple Groups I1 and 11' blueviolet actinide strip. The margin a t the overlapping of the Groups 111 and 111' blue cylinders may be left empty; students may write in the Lanthanides and actinides blup arahic numerals at the beginning of each series. The Groups IV and IV' green finished model is shown in Figure 3. Groups V and V' yellow From carbon through fluorineand from silicon through Groups VI and VI' orange Groups VII and VII' red chlorine the elements are in groups marked with the Group VIII triads line-ahaded in black. Roman numeral prime because their projections fall Scissors were used to cut from the right eclge above on the prime radii of the circular chart on the base of the numerals VII' to VIII and through the broken the large models. Carbon and silicon are directly above line below the short series. The rest of the broken the center of the large circle. Figure 4 shows a proline was followed and then the line above I and 0 was jection of the first short series and the first long series. cut to the left edge. The broken lines around the lan- The group numbers V and V', VI and VI', etc., do not
Even this model is fragile and took considerable time to assemble. To make the three-dimensional idea available for student use, a chart was made with the elements arranged in the order shown in Figure 2 so there is continuity without interruption a t 57 and 89 and no gap in the short series. To get it on a sheet 81/1 X 11inches the spiral was sacrificed. Students color the chart with pencils such as are used in their map making. The following color scheme worked out satisfactorily:
JOURNAL OF CHEMICAL EDUCATION
Figure 4
is not half that of the large one because in the priutiug the triads occupy three spaces, whereas in the two prcvious models the first and third members of the triads are above radii inserted between radii VII and VIII and between VIII and 1'. By turning the ends of the lanthanide and actinide strips forward theso series fit the diameter of the large cylinder quite well. This makes an interesting project in beginning chemistry, not only for those students who appreciate theory, hnt for those who need to use their hands to helu them to learn. They contribute to making the finished product and have the model as a memento of their chemistry course. ~
have t,he same significance as V-A and V-B,VI-A and VI-B as used on other charts of the periodic system. In the paper model the diamet,er of the small cylinder
~~
~
