Question

(a) Find the first excitation potential of He+ ion. (b) Find the ionization potential of Li++ ion.

Answer 1

(a) The first excitation potential of He++ ion is 40.8 V

(b) Ionization potential of Li++ ion is 122.4 V

Explanation:

Given data

To find ionization potential of He++ ion and Li++ ion

In the nth state, atom like hydrogen has the PE,

                        $\mathrm{V}=\frac{-13.6 Z^{2}}{n^{2}} e V$

Here, that atom has Z as the atomic number.

The atom should be excited to n = 2 from n = 1 state for the first excitation.  

So, the potential of excitation will be equal to the variance in the atom’s potential in n = 2 and n = 1 states.  

(a) He+ has the first excitation level:

-13.6Z² ($1-\frac{1}{2^{2}}$) eV = -10.2 Z² eV

⇒10.2 × Z²

First excitation potential of He++ ion = 40.8 V

(b) Li++ has the Ionization Potential = 13.6 V × Z²

Ionization potential of Li++ ion  = 122.4 V

Answer 2

Answer:

40.8 V

(b) Ionization potential of Li++ ion is 122.4 V

Explanation:

Given data

To find ionization potential of He++ ion and Li++ ion

In the nth state, atom like hydrogen has the PE,

\mathrm{V}=\frac{-13.6 Z^{2}}{n^{2}} e VV=

n

2

−13.6Z

2

eV

Here, that atom has Z as the atomic number.

The atom should be excited to n = 2 from n = 1 state for the first excitation.

So, the potential of excitation will be equal to the variance in the atom’s potential in n = 2 and n = 1 states.

(a) He+ has the first excitation level:

-13.6Z² (1-\frac{1}{2^{2}}1−

2

2

1

) eV = -10.2 Z² eV

⇒10.2 × Z²

First excitation potential of He++ ion = 40.8 V

(b) Li++ has the Ionization Potential = 13.6 V × Z²

Ionization potential of Li++ ion = 122.4 V