question_answer 1)

  In the following questions a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question. Assertion (A): Generally ionisation enthalpy increases from left to right in a period. Reason (R): When successive electrons are added to the orbitals in the same principal quantum level, the shielding effect of inner electrons (core of electrons) does not increase very much to compensate for the increased attraction of the electron to the nucleus. (a) Assertion is correct statement and Reason is wrong statement. (b) Assertion and Reason both are correct statements and Reason is correct explanation of Assertion. (c) Assertion and Reason both are wrong statements. (d) Assertion is wrong statement and Reason is correct statement.

Answer:

  (b) Ionisation enthalpy increases from left to right across the period due to decrease in atomic size. The electrons present within the subshell has almost same effective nuclear charge.