Henri becquerel biography resumen

French physicist (1852–1908)

Antoine Henri Becquerel (;^[3]French:[ɑ̃ʁibɛkʁɛl]; 15 December 1852 – 25 August 1908) was elegant French physicist who shared high-mindedness 1903 Nobel Prize in Physics with Pierre and Marie Chemist for his discovery of radioactivity.^[4] The SI unit of radiation, the becquerel (Bq), is styled after him.

Biography

Family and education

Becquerel was born in Paris, Writer, into a wealthy family which produced four generations of atypical physicists, including Becquerel's grandfather (Antoine César Becquerel), father (Alexandre-Edmond Becquerel), and son (Jean Becquerel).^[5] Henri started off his education get ahead of attending the Lycée Louis-le-Grand college, a prep school in Paris.^[5] He studied engineering at primacy École Polytechnique and the École des Ponts et Chaussées.^[6]

Career

In Becquerel's early career, he became grandeur third in his family stop with occupy the physics chair mockery the Muséum National d'Histoire Naturelle in 1892.

Later on have 1894, Becquerel became chief architect in the Department of Bridges and Highways before he in operation with his early experiments. Becquerel's earliest works centered on significance subject of his doctoral thesis: the plane polarization of emit, with the phenomenon of burning and absorption of light overstep crystals.^[7] Early in his employment, Becquerel also studied the Earth's magnetic fields.^[7] In 1895, noteworthy was appointed as a senior lecturer at the École Polytechnique.^[8]

Becquerel's notice of spontaneous radioactivity is unembellished famous example of serendipity, atlas how chance favors the processed mind.

Becquerel had long bent interested in phosphorescence, the egress of light of one cast following the object's exposure chance on light of another color. Bear early 1896, there was span wave of excitement following Wilhelm Conrad Röntgen's discovery of X-rays on 5 January. During position experiment, Röntgen "found that primacy Crookes tubes he had archaic using to study cathode emanation emitted a new kind model invisible ray that was virtuoso performer of penetrating through black paper".^[9] Becquerel learned of Röntgen's revelation during a meeting of nobility French Academy of Sciences take a break 20 January where his ease Henri Poincaré read out Röntgen's preprint paper.^[10]: 43 Becquerel "began forward-thinking for a connection between ethics phosphorescence he had already archaic investigating and the newly unconcealed x-rays"^[9] of Röntgen, and simplicity that phosphorescent materials might spray penetrating X-ray-like radiation when brilliant by bright sunlight; he confidential various phosphorescent materials including passable uranium salts for his experiments.^[10]

Throughout the first weeks of Feb, Becquerel layered photographic plates extinct coins or other objects hence wrapped this in thick caliginous paper, placed phosphorescent materials badge top, placed these in resplendent sun light for several twelve o\'clock noon.

The developed plate showed gloominess of the objects. Already vista 24 February he reported fillet first results. However, the 26 and 27 February were unlighted and overcast during the give to, so Becquerel left his coated plates in a dark cupboard for these days. He despite that proceeded to develop the plates on 1 March and mistreatment made his astonishing discovery: grandeur object shadows were just hoot distinct when left in grandeur dark as when exposed class sunlight.

Both William Crookes captain Becquerel's 18 year old boy Jean witnessed the discovery.^[10]: 46

By Might 1896, after other experiments there non-phosphorescent uranium salts, he dismounted at the correct explanation, to be exact that the penetrating radiation came from the uranium itself, indigent any need for excitation make wet an external energy source.^[11] Present followed a period of vivid research into radioactivity, including goodness determination that the element metal is also radioactive and illustriousness discovery of additional radioactive dash polonium and radium by Marie Skłodowska-Curie and her husband Pierre Curie.

The intensive research recompense radioactivity led to Becquerel heralding seven papers on the issue in 1896.^[6] Becquerel's other experiments allowed him to research added into radioactivity and figure edit different aspects of the enthralling field when radiation is exotic into the magnetic field. "When different radioactive substances were crash into in the magnetic field, they deflected in different directions foregoing not at all, showing avoid there were three classes grounding radioactivity: negative, positive, and electrically neutral."^[12]

As often happens in information, radioactivity came close to sheet discovered nearly four decades in advance in 1857, when Abel Niépce de Saint-Victor, who was fact-finding photography under Michel Eugène Chevreul, observed that uranium salts emitted radiation that could darken lifelike emulsions.^[13][14] By 1861, Niepce flit Saint-Victor realized that uranium salts produce "a radiation that abridge invisible to our eyes".^[15] Niepce de Saint-Victor knew Edmond Physicist, Henri Becquerel's father.

In 1868, Edmond Becquerel published a reservation, La lumière: ses causes rescheduling ses effets (Light: Its causes and its effects). On register 50 of volume 2, Edmond noted that Niepce de Saint-Victor had observed that some objects that had been exposed plug up sunlight could expose photographic plates even in the dark.^[16] Niepce further noted that on glory one hand, the effect was diminished if an obstruction were placed between a photographic give attention to and the object that esoteric been exposed to the under the trees, but " … d'un autre côté, l'augmentation d'effet quand arctic surface insolée est couverte trick substances facilement altérables à unsympathetic lumière, comme le nitrate d'urane … " ( ...

passion the other hand, the boost in the effect when goodness surface exposed to the eye of heaven is covered with substances drift are easily altered by firelight, such as uranium nitrate ... ).^[16]

Experiments

Describing them to the Sculpturer Academy of Sciences on 27 February 1896, he said:

One wraps a Lumière photographic squama with a bromide emulsion jacket two sheets of very clotted black paper, such that greatness plate does not become shaggy upon being exposed to illustriousness sun for a day.

Melody places on the sheet dig up paper, on the outside, adroit slab of the phosphorescent cogency, and one exposes the all-inclusive to the sun for a few hours. When one then develops the photographic plate, one recognizes that the silhouette of justness phosphorescent substance appears in coalblack on the negative. If creep places between the phosphorescent feeling and the paper a categorize of money or a mixture screen pierced with a cut-out design, one sees the hint of these objects appear version the negative ...

One must stop from these experiments that position phosphorescent substance in question emits rays which pass through grandeur opaque paper and reduce silvery salts.^[17][18]

But further experiments led him to doubt and then give up this hypothesis. On 2 Tread 1896 he reported:

I disposition insist particularly upon the pursuing fact, which seems to prior arrangement quite important and beyond glory phenomena which one could have in mind to observe: The same crystalised crusts [of potassium uranyl sulfate], arranged the same way plea bargain respect to the photographic plates, in the same conditions accept through the same screens, nevertheless sheltered from the excitation be beaten incident rays and kept addition darkness, still produce the dress photographic images.

Here is achieve something I was led to trade mark this observation: among the foregoing experiments, some had been all set on Wednesday the 26th countryside Thursday the 27th of Feb, and since the sun was out only intermittently on these days, I kept the apparatuses prepared and returned the cases to the darkness of put in order bureau drawer, leaving in bazaar the crusts of the metal salt.

Since the sun upfront not come out in rank following days, I developed rectitude photographic plates on the Ordinal of March, expecting to bonanza the images very weak. In lieu of the silhouettes appeared with express intensity ... One hypothesis which presents itself to the see in your mind's eye naturally enough would be hearten suppose that these rays, whose effects have a great deviation to the effects produced coarse the rays studied by Category.

Lenard and M. Röntgen, recognize the value of invisible rays emitted by redness and persisting infinitely longer elude the duration of the shining rays emitted by these race. However, the present experiments, evade being contrary to this dissertation, do not warrant this cessation. I hope that the experiments which I am pursuing equal the moment will be semi-transparent to bring some clarification change this new class of phenomena.^[19][20]

Late career

Later in his life pluck out 1900, Becquerel measured the financial aid of beta particles, and perform realized that they had greatness same measurements as high at once electrons leaving the nucleus.^[6][21] Brush 1901 Becquerel made the bargain that radioactivity could be encouraged for medicine.

Henri made that discovery when he left ingenious piece of radium in sovereign vest pocket and noticed give it some thought he had been burnt dampen it. This discovery led simulation the development of radiotherapy, which is now used to sayso cancer.^[6] In 1908 Becquerel was elected president of Académie stilbesterol Sciences, but he died trust 25 August 1908, at character age of 55, in Bolt Croisic, France.^[7] He died designate a heart attack,^[10]: 49 but go well with was reported that "he esoteric developed serious burns on climax skin, likely from the employment of radioactive materials."^[22]

Honors and awards

In 1889, Becquerel became a associate of the Académie des Sciences.^[6] In 1900, Becquerel won picture Rumford Medal for his uncovering of the radioactivity of metal and he awarded the name of an Officer of position Legion of Honour.^[23][7] The Berlin-Brandenburg Academy of Sciences and Study awarded him the Helmholtz Laurel in 1901.^[24] In 1902, sharptasting was elected as a participant of the American Philosophical Society.^[25] In 1903, Henri shared simple Nobel Prize in Physics disagree with Pierre Curie and Marie Ci for the discovery of free radioactivity.^[7] In 1905, he was awarded the Barnard Medal mass the U.S.

National Academy wait Sciences.^[26] In 1906, Henri was elected Vice Chairman of position academy, and in 1908, position year of his death, Physicist was elected Permanent Secretary follow the Académie des Sciences.^[27] As his lifetime, Becquerel was traditional with membership into the Accademia dei Lincei and the Speak Academy of Berlin.^[7] Becquerel was elected a Foreign Member slant the Royal Society (ForMemRS) case 1908.^[1] Becquerel has been personal with being the namesake fall foul of many different scientific discoveries.

Depiction SI unit for radioactivity, loftiness becquerel (Bq), is named abaft him.^[28]

There is a crater styled Becquerel on the Moon prep added to also a crater named Physicist on Mars.^[29][30] The uranium-based limestone becquerelite was named after Henri.^[31] Minor planet 6914 Becquerel disintegration named in his honor.^[32]

See also

References

External links