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ATOM IN MODERN SCIENCE
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of electricity, if put together, will cancel each other if a positron encounters an electron, the two will cease to exist as individual particles This process of mutual annihilation creates an intensive electro-magnetic radiation called gamma rays which carry away the original energy of the two particles Conversely, a pair of a positron and electron is created as a result of strong gamma radiations at the cost of the energy supplied by these rays These processes of mutual annhilation and pair formation confirm that the matter and energy are basically the same substance
Another kind of elementary particle called neutrinos have the merit of actually participating in various observable physical processes These particles carry no electric charge and their mass does not exceed the mass of an ordinary electron Such chargeless light particles could not be noticed by any existing physical apparatus Consequently they escaped from observation and were noticed only because of the deficit of energy which they carried away during what is known as beta-decay process
We can now make a complete list of the elementary particles participating in the structure of the material universe
First of all we have nucleons which represent the basic material particles They are either neutral or positively charged Plausibility of negatively charged nucleons is not entirely ruled out though they are not detected so far
Then we have the electrons and positrons representing the free charges of negative and positive clectncity respectively
There are also the niysterious nutrnos which carry no electric charge and are presumably lighter than clectrons
