Question

The energy of hydrogen atom in its ground state is – 13.6 eV. The energy of the level corresponding to the quantum number n is equal 5 is.

• A. – 5.40 eV
• B. – 2.72 eV
• C. – 0.85 eV
• D. – 0.54 eV

Answer 1

Answer: (D)

– 0.54 eV

Answer 2

$A = A_{0}\left( \frac{1}{2} \right)^{\frac{t}{T_{1/2}}} \Rightarrow \frac{1}{64} = \left( \frac{1}{2} \right)^{\frac{60}{T_{1/2}}}$⇒ $E_{5} = \frac{- 13.6}{5^{2}} = \frac{- 13.6}{25} = - 0.54\mspace{6mu} eV$