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The IE(1) of Li is 5.4 eV and IE(1) of H...

The `IE_(1)` of `Li` is `5.4 eV` and `IE_(1)` of `H` is `13.6 eV`. Calculate the charge acting on the outermost electron of `Li` atom.

Text Solution

Verified by Experts

For `Li`. electronic configureation si ` 1s^2 , 2s^2 ,` so given ionisation energy value is for `(n=2)`.
We know that : energy of `n^(th)` level `E_(eff)^(2)xxE_(1)`
`[( "Here" E_(1)="Energy of first orbit of" "H-atom"),(Z_(eff)="Effective nuclear cahrge")]`
or ` Z_(eff) = n sqrt(D_2/E_1)`
(Given: `E_1 =- 13. 6eV ,E_2 =- 5. 39eV ` and ` (n=2)`
` Z_(eff) = 2 xx sqrt((5. 39))/(13.6) = 1..26`
Thus effective nuclear charge si ` 1.26eV1` because `2s`.
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