A 440-Nm Spectral Line Is Produced by a Transition from an Excited

question 27

Multiple Choice

A 440-nm spectral line is produced by a transition from an excited state to the ground state.The natural line width of the spectral line is 0.020 pm.The average time the atom spends in the excited state is closest to which of the following? ( h = 1.055 × 10^-34 J • s = 6.59 × 10^-16 eV • s)

• A) 2.5 × 10^-6 s
• B) 2.5 × 10^-7 s
• C) 2.5 × 10^-8 s
• D) 2.5 × 10^-9 s
• E) 2.5 × 10^-10 s