Boltwood , Bertram Borden


Boltwood , Bertram Borden
(1870–1927) American chemist and physicist
Boltwood, the son of a lawyer, was born in Amherst, Massachusetts, and educated at Yale and the University of Munich. Apart from the period 1900–06, when he served as a private consultant, and the year 1909–10, which he spent in England with Ernest Rutherford at the University of Manchester, he devoted the whole of his academic career to Yale. He occupied the chair of physics (1906–10), the chair of radioactivity (1910–18), and the chair of chemistry from 1918 until his death by suicide in 1927.
Boltwood made a number of contributions to the study of radioactivity. The radioactivity of uranium and radium had been discovered in the 1890s by Henri Becquerel and Marie Curie. Starting in 1902 Rutherford and Frederick Soddy had shown that radium, uranium, and other radioactive elements broke down in a quite complicated sequence into other elements. Boltwood worked on the breakdown of uranium into radium, a process that Soddy had not found easy to demonstrate. Soddy had tried to obtain radium directly from uranium in 1904 and failed. Boltwood postulated that this was because uranium did not decay directly into radium but into some intermediate element, and began to search for it. After much effort Boltwood eventually found what he was looking for in ‘actinium X’, which, as it appeared different from anything else, he felt confident enough to claim as a new element and named it ‘ionium’ in 1907. This claim ran into trouble when ionium was found to behave very much like thorium and in 1908 it was shown by B. Keetman that if ionium and thorium are mixed together no chemical technique can separate them. Soddy decided the matter in 1913 when he was able to obtain a spectrograph of ionium and found it to be the same as thorium. Although he was wrong in detail, the general picture Boltwood had developed of the decay of uranium to radium was valid until superseded by Soddy's idea of the isotope.
One important byproduct of Boltwood's work was his demonstration in 1905 that lead was always found in uranium and was probably the final stable product of its decay. He argued that in minerals of the same age the lead–uranium ratio would be constant, and in minerals of different ages the ratio would be different. He calculated some estimates of the ages of several rocks based on the estimates then accepted for decay rates and came up with some good results. This was the beginning of attempts to date rocks and fossils by radiation measurements and other physical techniques, which have so revolutionized geology and archeology.

Scientists. . 2011.

Look at other dictionaries:

  • Boltwood, Bertram Borden — ▪ American chemist and physicist born July 27, 1870, Amherst, Mass., U.S. died Aug. 15, 1927, Hancock Point, Maine       American chemist and physicist whose work on the radioactive decay of uranium and thorium was important in the development of …   Universalium

  • Bertram B. Boltwood — Bertram Borden Boltwood (* 27. Juli 1870 in Amherst, Massachusetts, USA; † 14./15. August 1927 in Hancock Point, Maine (durch Selbstmord)) war ein US amerikanischer Radiochemiker. Leben und Wirken Bertram Boltwood studierte ab 1889 Chemie in Yale …   Deutsch Wikipedia

  • Bertram Boltwood — Bertram Borden Boltwood (né le 27 juillet 1870 à Amherst, Massachusetts, mort le 15 août 1927 à Hancock Point, Maine) est un radiochimiste américain. Il a établi que le plomb était l élément final de la famille radioactive de l uranium (celle de… …   Wikipédia en Français

  • Bertram Boltwood — Bertram Borden Boltwood (* 27. Juli 1870 in Amherst, Massachusetts, USA; † 14./15. August 1927 in Hancock Point, Maine (durch Selbstmord)) war ein US amerikanischer Radiochemiker. Leben und Wirken Bertram Boltwood studierte ab 1889 Chemie in Yale …   Deutsch Wikipedia

  • Bertram Boltwood — Infobox Scientist name = PAGENAME box width = image width =150px caption = PAGENAME birth date = July 27, 1870 birth place = Amherst, Massachusetts death date = 1927 death place = Hancock Point, Maine) residence = citizenship = nationality =… …   Wikipedia

  • Rutherford, Ernest, Baron Rutherford of Nelson, of Cambridge — ▪ British physicist Introduction born Aug. 30, 1871, Spring Grove, N.Z. died Oct. 19, 1937, Cambridge, Cambridgeshire, Eng.  New Zealand born British physicist considered the greatest experimentalist since Michael Faraday (Faraday, Michael)… …   Universalium

  • Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry       The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …   Universalium

  • geochronology — geochronologic /jee oh kron l oj ik/, geochronological, adj. geochronologist, n. /jee oh kreuh nol euh jee/, n. the chronology of the earth, as based on both absolute and relative methods of age determination. [1890 95; GEO + CHRONOLOGY] * * *… …   Universalium

  • Болтвуд, Бертрам — Бертрам Болтвуд (англ. Bertram Borden Boltwood; 27 июля 1870, Амхерст, США  15 августа 1927, Хэнкок, США)  американский учёный. Проходил стажировку в Англии у Эрнеста Резерфорда. Доказал, что радий является продуктом распада урана …   Википедия

  • List of named asteroids (A-C) — A List of named asteroids ordered alphabetically from A to C.See also: *List of named asteroids (D E) *List of named asteroids (F H) *List of named asteroids (I K) *List of named asteroids (L N) *List of named asteroids (O R) *List of named… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.