Page 118 - Miracles Within the Molecule
P. 118

HArun yahya

                    Adhesive Molecules

                    When a vase breaks when the bro ken parts approach one anoth er,
               a molec u lar attrac tion forms. Under nor mal con di tions, the two parts
               should adhere to each other as a result of this force stem ming from the
               mol e cu les draw ing near one anoth er, a force known as the "Van der
               Waals" force, which aris es from the attrac tion of the oppo site poles of
               atoms close to one anoth er. This attract ive force is rath er weak, yet when
               the attract ive for ces among count less atoms are all added togeth er, they
               give rise to a meas ur a ble adhe sive force.
                    In view of this infor ma tion, you might assume that when a vase's
               han dle is bro ken off, it would be enough to squeeze the two frag ments
               togeth er again. Shouldn't the high attrac tion aris ing between the atoms
               be enough to bond the two frag ments tight ly togeth er?
                    Generally, it shouldn't. You can never repair frag ments mere ly by
               hold ing them togeth er, because the dis tance between the sep a rat ed mol -
               e cu les must not exceed a few ang stroms. Only then can Van der Waals
                                                            -9
               force have any effect. One ang strom is just 4 x 10 inch, and even on sur -
               fa ces that you may assume to be very smooth, there are actu al ly peaks
                                                      -6
               meas ur ing up to 400 ang stroms (1.6 x 10 of an inch) high. Therefore,





                                                                 (Left side) Adhesive
                                                                 mate ri al seen under
                                                                 the micro scope





                                   When a glass is bro ken,
                                   the adhe sive between
                                   the parts allows a bond
                                   to form between the
                                   main body and the bro -
                                   ken piece. The two parts'
                                   stick ing  together  is
                                   noth ing but an increase
                                   in the molec u lar attrac -
                                   tion between the two.



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