How does radiation intensity vary with distance from the source?

Radiation intensity is governed by the inverse square law, which states that the intensity of radiation decreases with the square of the distance from the source. This means if you double the distance from the radiation source, the intensity of the radiation is reduced to one-fourth of its original value.

The reason behind this behavior is that as radiation travels away from the source, it spreads out over a larger area. The energy emitted by the source is constant, but as it disperses over an increasing surface area (which increases with the square of the radius), the intensity per unit area decreases according to this specific relationship.

Understanding this principle is crucial for ensuring safety in environments where radiation is used, as it informs operators on how to maintain safe distances from radiation sources in order to minimize exposure.