Page:Radio-activity.djvu/471

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 * |                 |          |       Nature of        | Chemical and Physical properties  |
 * Products    |λ(sec)^{-1}|   T    |        the rays        |          of the product           |
 * Uranium          |      —          |   —     |        α         |Soluble in excess of ammonium      |
 * [v]           |                  |          |                        | carbonate, soluble in ether.      |
 * Uranium X        |  3·6 × 10^{-7}   | 22 days  |   β and γ   |Insoluble in excess of ammonium    |
 * |            |                  |          |                        | carbonate, soluble in             |
 * [v]           |                  |          |                        | ether and water.                  |
 * Thorium          |       —         |    —    |        α         |Insoluble in ammonia.              |
 * [v]           |                  |          |                        |                                   |
 * Thorium X        |  2·0 × 10^{-6}   |  4 days  |        α         |Soluble in ammonia and water.      |
 * [v]           |                  |          |                        |                                   |
 * Emanation        |  1·3 × 10^{-2}   | 53 secs. |        α         |Chemically inert gas of heavy      |
 * |            |                  |          |                        | molecular weight. Condenses       |
 * |            |                  |          |                        | at -120° C.                       |
 * [v]           |                  |          |                        |} Deposited on bodies;             |
 * Thorium A        |  1·74 × 10^{-5}  | 11 hours |        no rays         |}  concentrated on the cathode in  |
 * |            |                  |          |                        |}  an electric field. Soluble in   |
 * [v]           |                  |          |                        |}  some acids; Th A more volatile  |
 * Thorium B        |  2·2 × 10^{-4}   | 55 mins. |α, β, γ|}  than Th B; shows definite       |
 * |            |                  |          |                        |}  electro-chemical behaviour.     |
 * [v]           |                  |          |                        |                                   |
 * Actinium         |      —          |    —    |        no rays         |Insoluble in ammonia.              |
 * [v]           |                  |          |                        |                                   |
 * Actinium X       |  7·8 × 10^{-7}   |10·2 days | α (and β?)  |Soluble in ammonia.                |
 * [v]           |                  |          |                        |                                   |
 * Emanation        |       ·17        |3·9 secs. |        α         |Behaves like a gas.                |
 * [v]           |                  |          |                        |} Deposited on bodies; concentrated|
 * Actinium A       |  3·2 × 10^{-4}   | 36 mins. |        no rays         |}  on the cathode in an electric   |
 * |            |                  |          |                        |}  field, soluble in ammonia       |
 * [v]           |                  |          |                        |}  and strong acids; volatilized   |
 * Actinium B       |  5·4 × 10^{-3}   |2·15 mins.|α, β, γ|}  at a temperature of 100° C.,    |
 * |            |                  |          |                        |}  A and B can be separated by     |
 * [v]           |                  |          |                        |}  electrolysis.                   |
 * [v]           |                  |          |                        |}  electrolysis.                   |
 * Radium           |       —         |1300 years|        α         |Allied chemically to barium.       |
 * [v]           |                  |          |                        |                                   |
 * Emanation        |  2·1 × 10^{-6}   | 3·8 days |        α         |Chemically inert gas of heavy      |
 * |            |                  |          |                        | molecular weight; condenses       |
 * [v]  } Active |                  |          |                        | at -150° C.                       |
 * Radium A } deposit| 3·85 × 10^{-3}  | 3 mins.  |        α         |} Deposited on surface of bodies;  |
 * [v]  } of     |                  |          |                        |}  concentrated on cathode in      |
 * Radium B } rapid |  5·38 × 10^{-4}  | 21 mins. |        no rays         |}  electric field; soluble in      |
 * [v]  } change |                  |          |                        |}  strong acids; B volatilized at  |
 * Radium C }       |  4·13 × 10^{-4}  | 28 mins. |α, β, γ|}  about 700° C., A and C at about |
 * [v]           |                  |          |                        |}  1000° C.                        |
 * Radium D } Active |      —         | about 40 |        no rays         |Soluble in acids; volatile below   |
 * [v]  } deposit|                  |  years   |                        | 1000° C.                          |
 * Radium E } of    |  1·3 × 10^{-6}   |  6 days  |   β and γ   |Non-volatile at 1000° C.           |
 * [v]  } slow   |                  |          |                        |                                   |
 * Radium F } change | 5·6 × 10^{-8}   | 143 days |        α         |Deposited on bismuth from          |
 * [v]           |                  |          |                        | solution; volatile at about       |
 * ?            |       —         |    —    |          —            | 1000° C., same properties as      |
 * |                 |          |                        | radio-tellurium and polonium.     |