241. Which of the following is an important source of gold ?

1. 1. Malachite

   
   
   

   2. Siderite

   
   
   

   3. Alluvial gravel

   
   
   

   4. Azurite

   
   
   

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   NA

   Correct Option: C

   NA

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242. The purple colour of [Ti(H₂O)₆]³⁺ ion due to

1. 1. Ttransfer of an electron

   
   
   

   2. Intermolecular vibrations

   
   
   

   3. Presence of water molecules

   
   
   

   4. Unpaired d-electron

   
   
   

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   NA

   Correct Option: D

   NA

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243. Which of the following is not a property of the transition elements ?

1. 1. Fixed valency

   
   
   

   2. Colour

   
   
   

   3. Paramagnetic

   
   
   

   4. None of these

   
   
   

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   NA

   Correct Option: A

   NA

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244. Silver is present in

1. 1. Limonite

   
   
   

   2. Pyrargyrite

   
   
   

   3. Magnetite

   
   
   

   4. Dolomite

   
   
   

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   NA

   Correct Option: B

   NA

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245. Beryl is an important mineral of

1. 1. Lithium

   
   
   

   2. magnesium

   
   
   

   3. beryllium

   
   
   

   4. Calcium

   
   
   

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   NA

   Correct Option: C

   NA

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