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Assertion: The third period contains onl...

Assertion: The third period contains only 8 electrons and not 18 like 4th period.
Reason: In III perriod filling starts from `3s^(1)` and complete at `3p^(6)` whereas in IV period it starts from `4s^(1)` annd complete after `3d^(10)` and `4s^(2)`.

A

If both assertion and reason are true annd the reason is the correct explanation of assertion

B

If both assertion and reason are true but reason is not the correct explanation of assertion

C

If assertion is true but the reason is false

D

if assertion is false but the reason is true

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The correct Answer is:
A
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VK JAISWAL ENGLISH-PERIODIC PROPERTIES-ASSERTION-REASON TYPE QUESTIONS
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  5. Assertion: helium atom has highest ionisation energy among all the ele...

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  6. Assertion: F^(-) ion has highest hydrated radius among the other halid...

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  7. Assertion: magnitude of electron gain enthalpy of oxygen is less than ...

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  8. Assertion: Formation of Cl^(-) ion is exothermic wheres O^(2-) ion for...

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  9. Assertion: The electron gain enthalpy of N is +ve while that of P is -...

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  10. Assertion: The formation of F((g))^(-) from F((g)) is exothermic, wher...

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  11. Assertion: Na^(+) and Al^(3+) are isoelectronic but ionic radius Al^3+...

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  12. Assertion: The third period contains only 8 electrons and not 18 like ...

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  13. Assertion: Cs and F(2) combines violently to form CsF. Reason: Cs is...

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  14. Assertion: Second E.A. for halogens is almost zero. Reason: Fluorine...

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  15. Assertion: F atom has less electron afffinity than Cl atom. Reason: ...

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  16. Assertion: Among the halogens bond energy of F(2) is minimum. Reason...

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  17. Assertion: The first ionization energy of Be is greater than that of B...

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  18. Assertion: Noble gases have highest ionization enthalpies in their res...

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  19. He and Be both have the same outer electronic configuration like ns^(2...

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  20. Assertion: the first enthalpy of aluminium is lower than that of magne...

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