JEE Advanced Physics: Structure of Atom and Periodic Table questions with solutions

Q1. Find the number of INCORRECT orders among the following: (i) IE of O(g) < IE of O-(g) (ii) IE of Ne(g) < IE of Ne+(g) (iii) IE of Na+(g) < IE of Ne(g) (iv) Atomic size of P(g) > atomic size of N(g) (v) Atomic size of Zn > atomic size of Hg (vi) (n + l) value of 5p orbital < (n + l) value of 6s orbital

1. 1
2. 2
3. 3
4. 4

Answer: 4

Statements (i), (iii), (v), and (vi) are incorrect: IE(O) > IE(O-), not less; IE(Na+) > IE(Ne); size of Hg > Zn (lanthanide contraction exception); (n+l) of 5p = 6 = (n+l) of 6s, so not strictly less. Thus 4 statements are incorrect.