26 



LIFE: ITS BEGINNINGS AND NATURE 



units which have been weighed, counted, 

 checked for speed, and measured for their 

 electrical nature. The significance of atomic 



Fig. 2-3. The possible structure of the hydrogen atom. 

 The proton with its positive charge lies at the center 

 and the negatively charged electron revolves about it. 



structure came to the attention of everyone 

 when physicists were able to manipulate 

 atoms in such a manner as to have them 



would be invisible, but because of their 

 terrific speed they would appear as a dim 

 blur, giving a vague limit to the entire 

 structure. In some atoms there would be 

 other concentric rings within the outer shell 

 and these would appear as hazy as the outer 

 shell; they might be intertwined with one 

 another. Only the speed of the electrons 

 would make these limits apparent, because 

 the electrons themselves seem to have very 

 little, if any, mass. They are "intangible 

 units of energy," whirling at unimaginable 

 speeds, yet maintaining remarkable sta- 

 bility. Atoms can be "smashed," as we all 

 know, if unbelievable amounts of energy 

 are directed at them. As a result of "smash- 

 ing," the nature of the atom itself changes. 

 The nucleus of the atom consists of a 

 dense cluster of positively charged parti- 



Fig. 2-4. A hypothetical explanation of how helium is formed by the combination of two 



neutrons with two hydrogen atoms. 



release tremendous amounts of energy in 

 the form of atomic explosions. 



One might think of the atom as a minia- 

 ture solar system with its relatively large, 

 heavy nucleus, the "sun," and its revolving 

 electrons, the "planets" ( Fig. 2-3 ) . Reminis- 

 cent of the universe, the most striking char- 

 acteristic of an atom is the vast amount of 

 space between the various particles of which 

 it is composed. If we imagine the atom to 

 be the size of a balloon 100 feet in diameter, 

 it would appear as a hazy, transparent 

 sphere. At the center would appear a 

 nucleus, the only clearly visible part, about 

 the size of a small marble. The electrons 



cles, protons, and uncharged particles, 

 neutrons (Fig. 2-4). These are held 

 together by some unexplained intra-nuclear 

 force. The protons and neutrons make up 

 almost all of the mass of the atom. For 

 every positively charged particle (proton) 

 in the nucleus there is an electron, which 

 carries a negative charge, in one of the 

 orbits. Thus the total atom is neutral, that 

 is, it carries no apparent charge. It is inter- 

 esting to note that all of the 98 elements 

 are made up of these vmits, differing one 

 from another only because of the relative 

 number and arrangements of protons, neu- 

 trons, and electrons. 



