21. Which is one of the correct sequences of wavelength of radiations?

1. 1. UV > Green > In > Hard X - rays

   
   
   

   2. IR > Green > UV > Hard X - rays

   
   
   

   3. UV > Hard X - rays > In > Green

   
   
   

   4. IR > Hard X - rays > Green > UV

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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22. The radius of an atomic nucleus is of the order of

1. 1. 10^-10 cm

   
   
   

   2. 10^-13 cm

   
   
   

   3. 10^-15 cm

   
   
   

   4. 10^-8 cm

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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23. Atomic size of the order of

1. 1. 10^-8 cm

   
   
   

   2. 10^-10 cm

   
   
   

   3. 10^-13 cm

   
   
   

   4. 10^-6 cm

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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24. Who discovered the Electron ?

1. 1. Chadwik

   
   
   

   2. Bohr

   
   
   

   3. Thomson

   
   
   

   4. Rutherford

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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25. ⁷Li₃ and ⁸Be₄ are called

1. 1. Isotopes

   
   
   

   2. Isobar

   
   
   

   3. Isotones

   
   
   

   4. None

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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