276. Which of the following alkaline earth metals has the highest ionic mobility in an aqueous solution ?

1. 1. Ba²⁺

   
   
   

   2. Mg²⁺

   
   
   

   3. Ca²⁺

   
   
   

   4. Be²⁺

   
   
   

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   NA

   Correct Option: A

   NA

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277. Iron rusts in the presence of

1. 1. O₂ and N₂

   
   
   

   2. O₂ and moisture

   
   
   

   3. Moisture only

   
   
   

   4. O₂ only

   
   
   

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   NA

   Correct Option: B

   NA

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278. Stainless steel contains

1. 1. Fe + Cr + Ni

   
   
   

   2. Fe + Ni + Cu

   
   
   

   3. Fe + Cr + Cu

   
   
   

   4. Fe + C + Ni

   
   
   

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   NA

   Correct Option: A

   NA

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279. Both lanthanides and actinides have their last valance electron in

1. 1. (n-1)d

   
   
   

   2. (n-2)f

   
   
   

   3. ns

   
   
   

   4. np

   
   
   

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   NA

   Correct Option: B

   Na

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280. The most common and stable oxidation state of lanthanides is

1. 1. +1

   
   
   

   2. +2

   
   
   

   3. +3

   
   
   

   4. +4

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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