Question

In Bohr's atomic model, the energy of the electron is 'E' in the second orbit of hydrogen atom. So the energy of the electron in the third orbit of helium atom \((Z = 2)\) will be

• A. \(\frac{16\,E}{3}\)
• B. \(\frac{16\,E}{9}\)
• C. \(\frac{4\,E}{3}\)
• D. \(\frac{4\,E}{9}\)

Hint:

Count the possible transitions from n = 3 to lower levels.

Answer 1

The Correct Option is B

Step 1: Combination count:
Choose any two of the three levels as start and end: $\binom32 = 3$.

Step 2: Result:
There are 3 lines (B).

Final Answer:
3. \[ \boxed{3} \]