IAT IISER2026ChemistryStructure of Atom
What is the ratio of the velocity of an electron in the fourth orbit of Be ³⁺ to the velocity of the electron in the second orbit of He ^+ ?
Options
- A1:1
- B1:2
- C6:1
- D3:2
Correct answer
A. 1:1
Step-by-step solution
The velocity of an electron in the n -th orbit of a hydrogen-like ion is given by v Z n . For Be ³⁺ , Z = 4 and n = 4 . v_ Be ³⁺ 4 4 = 1 For He ⁺ , Z = 2 and n = 2 . v_ He ⁺ 2 2 = 1 The ratio of their velocities is v_ Be ³⁺ v_ He ⁺ = 1 1 = 1:1 . Answer: 1:1