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AP EAMCET202124 Aug 2021Evening ShiftChemistryClassification of Elements and Periodicity in PropertiesActual

Assertion (A) Helium and beryllium have similar outer electronic configuration n s^2 . Reason (R) Both are chemically inert

Options

  1. ABoth (A) and (R) are correct and (R) is the correct explanation of (A) .
  2. BBoth A and R are correct but R is not the correct explanation of A .
  3. CA is correct but R is incorrect.
  4. DBoth A and R are incorrect.

Correct answer

C. A is correct but R is incorrect.

Step-by-step solution

The electronic configuration of aligned He & =1 s^2 Be & =1 s^2 2 s^2 aligned Both have n s^2 configuration but helium is inert because its only shell i.e. 1 s is completely filled while Be is a reactive alkaline earth metal. So, A is correct but R is incorrect.

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