Question

The value of $I{E}_1$ for $He$ is 2372 kJ/mol, the value of $I{E}_2$ should be:

• A. 5248 kJ/mol
• B. 4852 kJ/mol
• C. 5648 kJ/mol
• D. 4508 kJ/mol

Answer 1

Answer: (A)

5248 kJ/mol

Since ${IE}_2$ is around $54$eV (Bohr's Theory)

Or $\sim 5248$kJ/mol (Unit conversion)

E=$\mathrm{13.6.}\frac{Z_{eff}^2}{n_2}(Z_{eff}\approx 1.7)n=1$