26. The mass of one atom of hydrogen is approximately

1. 1. 1 g

   
   
   

   2. 1.5 g

   
   
   

   3. 1.6 x 10^-24 g

   
   
   

   4. 3.3 x 10^-24 g

   
   
   

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   NA

   Correct Option: C

   NA

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27. The isotopes of chlorine with mass number 35 and 37 exist in the ratio of

1. 1. 1 : 2

   
   
   

   2. 2 : 3

   
   
   

   3. 3 : 1

   
   
   

   4. 3 : 4

   
   
   

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   NA

   Correct Option: C

   NA

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28. Which one is the pure element

1. 1. glass

   
   
   

   2. cement

   
   
   

   3. sodium

   
   
   

   4. none of these

   
   
   

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   NA

   Correct Option: C

   NA

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29. Air is

1. 1. Compound

   
   
   

   2. element

   
   
   

   3. mixture

   
   
   

   4. solution

   
   
   

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   NA

   Correct Option: C

   NA

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30. Name the scientist who stated that matter can be converted into energy .

1. 1. Boyle

   
   
   

   2. Lavoisier

   
   
   

   3. Avogadro

   
   
   

   4. Einstein

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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