Question

Ionisation energy of He⁺ is 19.6 × 10⁻¹⁸ J atom⁻¹. The energy of the first stationary state (n = 1) of Li²⁺ is
(a) 4.41 × 10⁻¹⁶ J atom⁻¹
(b) –4.41 × 10⁻¹⁷ J atom⁻¹
(c) –2.2 × 10⁻¹⁵ J atom⁻¹
(d) 8.82 × 10⁻¹⁷ J atom⁻¹

Answer 1

Ionization energy of He+=19.6×10−18J/atom−1He+=19.6×10−18J/atom−1

IE = E1(forH)×Z2E1(forH)×Z2

E1×4=19.6×10−18JE1×4=19.6×10−18J

E1(forLi2+)=E1forH×9E1(forLi2+)=E1forH×9

=19.6×10−184×9=19.6×10−184×9

=−44×10−18J=−44×10−18J

−4.41×10−17Jatom−1−4.41×10−17Jatom−1

B✔✔✔✔