MONOG RAP H S 0N INORGANIC A ND P H YS I CAL CH E MI S TR Y D . so . T H E C H E M I ST R Y O F T H E R A D I O - E L E M E N T S PA RT I M ONOG RA PH S ON INORG ANIC AND PH YSICAL CH EM IST RY E BY ALEXA Ph . D . DE R D M . FI LAY A D Sc . DITED N N , . , . , T H E E M R T H - CH IST Y O F E RA DIO E LE ME NTS . By F REDER CK S ODD M . A F R. S I Y , . P art I . - Par II . T H E RAD O ELEMENT S AN D ER OD C L A . 25 . t I T H E P I I W. net Two P in o V l arts ne o ume. PE R-A S . S c . C AND R A S . B T L R D E . S R ID TH I S LT y ATE P ICE, , Ph . D . F I C . s . , . 3 net . P . M . h S . D RESS RE . AL X R F L Y M A O OTIC P U By E ANDE IND A , , , O . Sc . net . T HE V S S F U S . B ALB R E R I CO ITY O LIQ ID y E T NEST DUNSTAN , D . Sc . d F R NAN B RNA R O B s. net . Sc . an E D D E D H LE . I T , 3 E R ME A C C M S . B C L H . B . se. INT T LLI O POUND y ECI DESCH , With I Fi ures 1 7 g . 3 . net . R S H R B . C . L P E E A E . L CT OLYTIC DIS OCI TION T O Y y ! PHI I , In r ara n Sc . ti D . [ [ ep o . E . C T H E S A E M RY F F AME . B PHY IC L CH IST O L S y l OATES, M In w ara ti on Sc . r p p A S . B . W. M LL R D S c. I n r rati CL Y y J E O , [ p epa on . D . A A A . B W E . S . U R c M E R . R S . OL CUL SSOCI TION y T NE , [I ni nf arc ti on . M . A Y S F A REA S . P N . A A S G S . C T L I O CTION By D L CHA MA , I n r arati [ p ep on . T HE E LE CT R O -CI—IE M IS T RY O F NON -AQU E OU S SOLU M B NS B A M S W . C A N . TIO . y J I A S S S E M . B R G S N R CAT LY IS IN LIQUID Y T S y GEO E E TE , B Sc. mn . f : F p mc D . Sc o T H E RA RE EART ME A S . S H T L By J , , I n r arati n. th e Bedford College for Wo men. [ p ep o u m : are i n r ar Other Vol e p ep ati on. LON MA NS RE E AND . G , G N CO LONDON NEW OR K BO MB A CALC U TT A AND M ADRAS . Y . Y. , C 5 67956 1 T H E C H EM IST RY OF T H E RA D IO-ELEM EN T S IC . F D K S Y F R S . OD D . RE ER , LATELY LECTU RER I N P H Y S I CAIJ UH E MI S TR Y A ND RAD I OACTIV ITY I N T H E U N I V ERSITY OF G LAS G OW : P RO F ESSOR OF CH EM I STR N ERS T OF A'B ERDEE N Y, U IV I Y PA RT I S E COND EDITION [RE V ISED AN D LARG ELY REWRI TT E N! L N G M S G N A N D C O O A N . , R E E P A T E R T E R R O W L O D O N 3 9 N O S , N F RT H AV EN E 30T H ST REET NEW RK O U U , YO B M B Y LC U T AND M D R S O A , CA T A , A A I 917 All righ ts reserved P REFAC E T O NEW E DI T ION OF PA RT I T HE Ch emistry of the Radio -E lements was first published E arl i as a single volume in 1 91 1 . y in 1 91 3 the mp o rtant generalisation was made which connects the chemical nature of the radio -elements with the sequence of changes in which they result, and which has given rise to the theory of isotopic Law elements, and thrown a fresh light on the Periodic . These discoveries formed the subj ect of a new volume, pub s 1 1 li h ed at the end of 9 3, as Part I I of the Chemistry of ‘ R -E the adio lements, the original volume thus becoming Part I . In 1 1 n 9 4 , a new edition of Part I bei g called for, the present volume was written . The whole subject can now be presented much more clearly and completely than in 1 1 1 9 , and in consequence Part I has had to be largely rewritten from the new point of view . But whilst the general mode of presentation has been much modified, the ground already covered in detail in Part I I has been , as far n as possible , avoided in the prese t volume , which concerns itself rather with the practical consequences than with the theoretical significance of the new generalisations . I n addition , much new matter has been added , especially in connection with the a rays and recent electro and co llo ido S m chemical researches on the radio elements . o e of the topics b ut briefly dealt with before have been considerably new amplified , and many members of the disintegration series, vi TH E CHE MISTR Y OF TH E RA DIO-EL E ME NTS n n n 1 1 1 . unk ow i 9 , have had to be included There is reason to hope that something approaching completeness has now been attained with regard to these numerous and involved successive products , and though much remains to be done , it will is unlikely that many more be discovered . FRE DERICK SODDY . October 1914 . CONT ENT S P R EFACE G ENER AL DESCR I PTION OF RADIOACTI V ITY R V C P R F AV R G L F ADIOACTI E ONSTANTS , E IODS O E A E I E AND RADIOACTIV E EQUI LI BR IUM E NUMER ATION AND NOMENCLATUR E OF THE R ADIO -E LEMENTS — P R ELIMINA R Y DESCR IPTION OF THE DISINTEG R ATION SER IES PHYSICAL M ETHODS OF SEPAR ATION T H E CHEMICAL CHAR ACTER OF THE RADIO -ELEMENTS A R P EL R COLLOI D o -C E R Y F R DSO TION , ECT O AND H MIST O ADIO ELEMENTS SYSTEMATIC DESC R IPTION OF THE RADIO -ELEMENTS U RANIUM (U ) R X R X U ANIUM 1 AND U ANIUM 2 U R ANIUM Y I ONIUM (I o ) RADIUM (RA ) RADIUM EMANATION “ ” RADIUM ACTI V E DEPOSIT RADIO-LEAD OR RADIUM D R ADIUM E PO LONIUM (RADIUM F) T HOR IUM (T H ) MESOTHO R IUM 1 M ESOTHO R I U M z RADIOTHO R IUM ' SYSTEMATI C DESCR IPTION OF THE RADIO-ELEMENTS (zontznued) T HO R IUM X T HO R IUM EMANATION “ T HO R IUM ACTI V E DEPOSIT ACTINIUM RADIO-ACTINIUM ACTINIUM X ACTINIUM EMANATION “ ACTINIUM ACTI V E DEPOSIT T H E U LTIMATE PRODUCTS — ATOMIC WEIG HT o r LEAD 1 40 POTASSIUM AND R UBIDIUM REFE RENCES R F D R R A t and a wal CHA TS O ISINTEG ATION SE IES f . T H E C H E M I S T R Y O F T H E R A D I O - E L E M E N T S P A R T I G ENER A L D E S CR I P TI ON OF R A D I O A CTI V I TY RAD IOACT IV ITY has introduced into the science of chemistry r a new conception . The adioactive elements are radio active because they are in progress of spontaneous change . The chemistry of the radio - elements is concerned largely with the nature of the products of these changes , their ' isolation and separate identification . The property of radioactivity was discovered by M 1 . Henri Becquerel in 1 8 96 for compounds of the element n uranium , which he found to be spontaneously emitti g new X- kinds of radiation , very much allied to the rays in their Th u s general nature . the new radiations pass to varying extent through all matter, quite independently of whether it is opaque or transparent to light . The new radiations , in addition to the properties possessed by light of acting on a a photographic plate and of causing cert in substances , like fl u o resce X- the platinocyanides , to , resemble the rays also in “ e ionising the air and other gases , r ndering them , for the time being , partial conductors of electricity , and causing them , for example , to discharge a gold leaf electroscope .