An Easily Contructed Cube Model Shukichi Yamana' Faculty of General Education. Kinki University. Kowakae, Higashi Osaka 577, Japan
Makoto Kawaguchi IDEC IZUMl Corporation, Mikuni-honmachi. Yodogawa-ku, Osaka 532, Japan
A model of a cube which is necessaw for teaching stereochemistry (especially of inorganic compounds) can Jbe made easilv, b y using a sealed, e m p t y envelope. T h e steps (illustrated ii t h e f&re) are given below. 1) The envelope is folded dawn the center lengthwise, and the middle points of the base AB and top CD, are marked E and F , respectively. 2) The middle points of the left- and right-hand sides of the envelope are marked G and H , respectively, and the intersection of the lines GH and EF is marked I. 3) The lower part of the envelope is folded up so that Lines IG and IE lie just on lines IF and IH, respectively. 4) The new corners on the left- and right-hand sides of the envelope are marked J and K , respectively. 5 ) The envelaoe is flattened out. 6, The horizokl line JL, perpendicular to the Id-handsideofthe envelope at J . 1% drawn. 7) Another hurirontal line MK, perpendicular to the right-hand side of the envelope at K , is drawn. 8) The intersection of IinesEF and J L is marked N and that of lines EF and MK is marked 0. 9) The intersection of the left-hand side of the envelope and the extension of line HO is marked P. 10) T h p hormontal linp PQ, perpendicular tn the left-hand side of the envelope at P, i%drawn,and the intersection oflines EFand I'Q is marked R. 11) The intersection of lines JI and GNis marked S and that of lines NH and IL is marked T .
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Journal of Chemical Education
12) The intersection of lines MR and PO is marked U and that of lines OQ and RK is marked V . 13) The upper and lower parts of the envelope are cut off along the two lines passing ( S and T ) or ( U and V ) ,respectively. 14) The remaining portion is folded both backward and forward along lines GS, M T , UH, V K , MU, GV, S K , TH, GH, MK, and the original center line including IO. 15) On the back of the envelope, the points corresponding to S , T, I , 0 , U , and V are marked S*, T*, I*, 0 * , U*, and V * ,respeetivelv. 16) oblique lines are drawn to shade eight isosceles triangles (SIT and OUV on the front, S*I*T* and O*U*V* on the hack, and SGS*, THT*, UMU*, and VKV* on both sides). 17) The right- and left-hand sides of the envelope are pushed toward each other so that four lines (GM,IO,HK, and I*O*) form four parallel sides of a cube. 18) ihur points S , 7..P , and S' are pushed uerthernnd the shaded creased innngles (SIT, THT', 'PI'S*, and S-GSj are fdded inside. The sides are taped together to form the upper half of thp cube. 19) Finally, four points U,V , V*, and U' are pushed together and the shaded creased triangles (OUV, KVV*, O*V*U*, and MU*U) are folded inside. The sides are taped together to form the lower half of the cube.
' Author to whom correspondence should be directed.
