________________
- ATOM IN MODERN SCIENCE 27
NUCLEUS—THE HEART OF ATOM
Let us now turn to a more detailed study of the nucleus-the heart of every atom Whereas the struclure of the outer body of the atom can be to a certain extent compared to a miniature planetary system, the structure of the nucleus itself presents an entirely different picture It is clear first of all that the forces holding nucleus together are not electrical, since the protons are all positively charged, thus repelling each other The electrical repulsion force in the nucleus, known as the coulomb force, varies inversely as the square of the distance separating the positively charged particles Prof E Soddy, has figured out that two grams of protons placed at the opposite poles of the earth would repel each other with a force of twenty-six tons
Therefore there must exist, between the constituent parts of the nucleus, forces of some other kind, which must be many times greater than the coulomb force These are generally known as “cohesive forces" and are similar to those encountered in ordinary Liquids causing the phenomenon of surface tension In the atomic nuclei we have similar forces of much greater magnitudes acting as the cosmic cement which prevents the breaking up of the nucleus under the action of electric repulsion between the protons Thus, if we assume the nuclei of different elements to be droplets of a universal “nuclear fluid"and the density of such a fluid will be 24X10 3 times that of the water Its surface tension forces will be about 1018 times larger than those of water
It must be remembered that all protons in the nuclei are positively charged and the electric forces of repulsion between them try to disrupt the nucleus into its constituents These electric forces are coun
