Question

Consider one He* ion in excited state (n = 5).
Which of the following observations will hold true
as per the Bohr's model​

Answer 1

Answer:

The electronic separation from the center of the nucleus is more than 6Å.

Explanation:

A multitude of He+ will produce 10 possible emission lines. A single He+ can produce a maximum of 4 lines (not more)

                           5→4→3→2→1

              En = − 13.6z² / n²  =  − 13.6 × 2² / 5²

                 = − 13.6 × 4 / 25 = − 2.176 eV

                  ∴ IE = +2.176 eV > 2eV

                       1/λ = RZ² [1 / n²₁ − 1 / n²₂]

                       1/λ = R.4 [1 / 4² − 1 / 5²]

                            1/λ = 4R [9 / 16 × 25]

                1/λ = 16 × 25 /4 × 9 × R = 100/9R > 10/R

                       rⁿ = 0.53 × n²/Z = 0.53 × 5² / Z

                                  = 6.625Å > 6°A