| rock | 0.60 |
| soil | 0.47 |
| small amounts | 0.44 |
| water | 0.38 |
| fluorosilicic acid | 0.26 |
| phosphate rock | 0.25 |
| sample | 0.09 |
| drop on hiroshima | 0.50 |
| occur in the earth's cr… | 0.50 |
| give atomic weapons | 0.49 |
| occur in differing forms | 0.46 |
| occur in seawater | 0.39 |
| give off energy | 0.38 |
| undergo fission | 0.37 |
| become in last fifty ye… | 0.35 |
| absorb neutron | 0.33 |
| remain in the ground | 0.33 |
| More » |
| some forms of cancer | 0.36 |
| 92 protons | 0.53 |
| fissionable isotope | 0.49 |
| atomic number of 92 | 0.25 |
| a chemical element | 0.56 |
| metal | 0.45 |
| common metal | 0.40 |
| heavy metal | 0.40 |
| fissile | 0.28 |
| highest-numbered element | 0.26 |
| 51st element | 0.25 |
| mined | 0.75 |
| enriched | 0.73 |
| removed | 0.67 |
| found as uranium-238 | 0.63 |
| mined in the united sta… | 0.60 |
| used as fuel | 0.56 |
| used by nuclear power p… | 0.51 |
| found on earth | 0.49 |
| separated | 0.49 |
| imported | 0.49 |
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| water fluoridation | 0.20 |