Question

The energy of an electron in the ground state (n=1) for He⁺ ion is -xJ, then that for an electron in n=2 state for Be³⁺ ion in J is:

• A. -x
• B. \(-\frac{x}{9}\)
• C. -4x
• D. \(-\frac{4}{9}x\)

Answer 1

The Correct Option is A

Correct option is (1) -x

E_n = -R_H (Z² / n²) J

For He⁺ (n = 1), E_n = -x = -R_H (2² / 1²) = -4R_H

∴ R_H = x / 4

For Be³⁺ (n = 2), E_n = -R_H (Z² / n²) J

= - (x / 4) × (4 × 4 / 2 × 2) = -x J