Photon Emission | MCQs

Explanation

When an electron from a higher shell fills a vacancy in an inner shell, it emits a photon with a specific energy.

These are called characteristic X-rays because their energy depends on the atomic structure of the element.

Explanation

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