Radioactivity is the process by which an unstable atomic nucleus loses energy by radiation. It is measured in becquerels (Bq).
1 FP = 100 R 
1 R = 0.01 FP 
उदाहरण: 
कन्वर्ट 15 Fission Products से Roentgen:
15 FP = 1,500 R 
| Fission Products | Roentgen | 
|---|---|
| 0.01 FP | 1 R | 
| 0.1 FP | 10 R | 
| 1 FP | 100 R | 
| 2 FP | 200 R | 
| 3 FP | 300 R | 
| 5 FP | 500 R | 
| 10 FP | 1,000 R | 
| 20 FP | 2,000 R | 
| 30 FP | 3,000 R | 
| 40 FP | 4,000 R | 
| 50 FP | 5,000 R | 
| 60 FP | 6,000 R | 
| 70 FP | 7,000 R | 
| 80 FP | 8,000 R | 
| 90 FP | 9,000 R | 
| 100 FP | 10,000 R | 
| 250 FP | 25,000 R | 
| 500 FP | 50,000 R | 
| 750 FP | 75,000 R | 
| 1000 FP | 100,000 R | 
| 10000 FP | 1,000,000 R | 
| 100000 FP | 10,000,000 R |