Question

The ionisation energy of a hydrogen atom is 13.6 ev.The energy of the ground level in doubly ionised lithium is...

Answer 1

Bohr’s model can be helpful in this.

According to this E= - 13.6 * z2/n2

So, in this the E is equal to energy of electron in nth shell of atom whose atomic number is z.

Now, same amount of energy with opposite sign must be given to electron in order to remove it. I.E. = 13.6 Z2 eV

 Since for Lithium, Z=3

Therefore, you get I.E. = 122.4 eV

Answer 2

Answer:

10.2 eV

Explanation:

Ionization energy = 13.6 eV      

i.e. 1 st energy state = – 13.6 eV

Energy of 1st excited state i.e. 2 nd orbit = –3.4 eV

so, E 2 – E1 = – 3.4 + 13.6   =    10.2 eV

let me know if I am wrong  

if you don't understand  try to read it