Radioactivity and Rutherford Experiment

 

What is Radioactivity ?

Radioactivity is a process in which some elements of nature dissociate itself in the form of Unseen rays. Such elements are called Radioactive Element. All those elements which have Atomic number more than 82 Except Atomic number 43 (Technetium) are called Radioactive element. 

Atomic number 83 (Bismuth) to 118 (Oganesson).  

In 1896, Antoine Henri Becquerel discovered Radioactivity. Hence, he is Father of Radioactivity.

he saw dissociate the Pitchblende (U3O8). Pitchblende is the ore of Uranium.

Note : Uranium is the first radioactive Element.

Radium :- Radium is second radioactive element. It discovered by Madam Curie in 1897. Hence, she is call Mother of Radioactivity and she got two noble prize in Physics (1903) and Chemistry (1911). Radium word comes from "Ray".

Rutherford Experiment (1899) 

Rutherford placed radium between the Electric fields which was going from positive to negative. he saw 3 kind of radiations some of them go towards positive charge of electric field that is Beta rays Because Beta ray has negative charge hence Beta ray attracted towards positive charge of Electric Fields and some of them go toward negative charge of electric field that is Alpha rays because Alpha ray has positive charge hence Alpha ray attracted towards Negative charge of Electric Fields and few of them go separately they did not go positive or negative charge that is Gamma rays because Gamma ray has no charge hence Gamma ray did not attract.

Alpha ray is equal to charge of 2 proton.

Beta ray is equal to charge of 1 Electron.

Penetrating Power : Maximum Penetrating Power of Gamma Ray than Beta ray and least in Alpha ray.

Gamma > Beta > Alpha.

Gamma ray = It can cross 100 cm wide Metal sheet.

Beta ray = It can cross 10 cm wide Metal sheet.

Alpha ray = It can easily stop by thin metal sheet.

Note :- Gamma ray is used in Cancer Treatment.   

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