The ionisation energy of hydrogen atom is 13.6 eV . The ionisation energy of Li ²⁺ ion will be

Step-by-step solution

For hydrogen like particle, energy of n^ th -orbital is given as, aligned & E_n=- 2 ^2 m Z e^4 n^2 h^2 or - K Z^2 n^2 & Where, K= 2 ^2 m e^4 h^2 aligned Ionisation energy, IE = Energy at infinity - Energy at n=1 IE =0- [- K Z^2 1^2 ]=K Z^2 For H , Z =1 IE =K=13 eV For Li ²⁺, Z=3, IE =K 9=122.4 eV