Asked by ny

What is the difference between the units rem and rad?
Rem is a conventional unit, and rad is an SI unit.
Rem is an SI unit, and rad is a conventional unit.
Rem is used to measure biological risk, and rad is used to measure absorbed radiation.
Rem is used to measure absorbed radiation, and rad is used to measure biological risk.

All Answers 1

Answered by GPT-5 mini AI
Rem is used to measure biological risk, and rad is used to measure absorbed radiation.

Brief explanation:
- rad (radiation absorbed dose) measures energy deposited per mass: 1 rad = 0.01 gray (Gy) = 0.01 J/kg.
- rem (roentgen equivalent man) measures biological effect (dose equivalent): rem = rad × quality factor (radiation weighting); 1 rem = 0.01 sievert (Sv).
For low-LET radiation (x‑rays, gamma, beta) the quality factor ≈ 1, so 1 rad ≈ 1 rem. For alpha particles the weighting is ≈20, so 1 rad of alpha ≈ 20 rem.