An atom can radiate at any time after it is excited. It is found that in a typical case, the average excited atom has a lifetime of about 10^(-8) s. That is, during this period it emits a photon and is de-excited. What is the minimum uncertainty delta-v in the frequency of the photon?

8 x 10^6 Hz

8 x 10^8 Hz

8 x 10^4 Hz

None of these

Using the Heisenberg Uncertainty Principle:

ΔE * Δt >= h/4π

where ΔE = h * Δv (energy uncertainty) and Δt = 10^(-8) s (lifetime)

h * Δv * 10^(-8) >= h/4π

Δv >= 1/(4π * 10^(-8))

≈ 8 x 10^6 Hz