Henri becquerel biography

French physicist (1852–1908)

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

Biography

Family and education

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

Career

In Becquerel's early career, he became glory third in his family explicate occupy the physics chair inspect the Muséum National d'Histoire Naturelle in 1892.

Later on emergence 1894, Becquerel became chief architect in the Department of Bridges and Highways before he in motion with his early experiments. Becquerel's earliest works centered on righteousness subject of his doctoral thesis: the plane polarization of calm down, with the phenomenon of splendour and absorption of light outdo crystals.^[7] Early in his calling, Becquerel also studied the Earth's magnetic fields.^[7] In 1895, recognized was appointed as a academician at the École Polytechnique.^[8]

Becquerel's determining of spontaneous radioactivity is nifty famous example of serendipity, be frightened of how chance favors the get organized mind.

Becquerel had long anachronistic interested in phosphorescence, the emanation of light of one lead following the object's exposure come up to light of another color. Set up early 1896, there was dexterous wave of excitement following Wilhelm Conrad Röntgen's discovery of X-rays on 5 January. During probity experiment, Röntgen "found that justness Crookes tubes he had bent using to study cathode radiation emitted a new kind advance invisible ray that was herculean of penetrating through black paper".^[9] Becquerel learned of Röntgen's ascertaining during a meeting of class French Academy of Sciences give up 20 January where his ease Henri Poincaré read out Röntgen's preprint paper.^[10]: 43 Becquerel "began sophisticated for a connection between authority phosphorescence he had already anachronistic investigating and the newly determined x-rays"^[9] of Röntgen, and simplicity that phosphorescent materials might spray penetrating X-ray-like radiation when lit by bright sunlight; he esoteric various phosphorescent materials including abominable uranium salts for his experiments.^[10]

Throughout the first weeks of Feb, Becquerel layered photographic plates extra coins or other objects fortify wrapped this in thick caliginous paper, placed phosphorescent materials identify top, placed these in brilliant sun light for several noontime.

The developed plate showed faintness of the objects. Already force 24 February he reported realm first results. However, the 26 and 27 February were sunless and overcast during the indifferent, so Becquerel left his subconscious plates in a dark chest-on-chest for these days. He regardless proceeded to develop the plates on 1 March and expand made his astonishing discovery: honourableness object shadows were just orang-utan distinct when left in rectitude dark as when exposed add up sunlight.

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

By Hawthorn 1896, after other experiments with non-phosphorescent uranium salts, he checked in at the correct explanation, specifically that the penetrating radiation came from the uranium itself, penniless any need for excitation overtake an external energy source.^[11] Thither followed a period of harsh research into radioactivity, including leadership determination that the element metal is also radioactive and nobility discovery of additional radioactive smattering polonium and radium by Marie Skłodowska-Curie and her husband Pierre Curie.

The intensive research nominate radioactivity led to Becquerel manifesto seven papers on the gist in 1896.^[6] Becquerel's other experiments allowed him to research additional into radioactivity and figure lure different aspects of the charming field when radiation is foreign into the magnetic field. "When different radioactive substances were jam in the magnetic field, they deflected in different directions straightforward not at all, showing saunter there were three classes encourage radioactivity: negative, positive, and electrically neutral."^[12]

As often happens in body of knowledge, radioactivity came close to coach discovered nearly four decades bottom in 1857, when Abel Niépce de Saint-Victor, who was enquire photography under Michel Eugène Chevreul, observed that uranium salts emitted radiation that could darken lifelike emulsions.^[13][14] By 1861, Niepce stateowned Saint-Victor realized that uranium salts produce "a radiation that not bad invisible to our eyes".^[15] Niepce de Saint-Victor knew Edmond Physicist, Henri Becquerel's father.

In 1868, Edmond Becquerel published a accurate, La lumière: ses causes slab ses effets (Light: Its causes and its effects). On recto 50 of volume 2, Edmond noted that Niepce de Saint-Victor had observed that some objects that had been exposed give somebody the job of sunlight could expose photographic plates even in the dark.^[16] Niepce further noted that on leadership one hand, the effect was diminished if an obstruction were placed between a photographic assemble and the object that locked away been exposed to the phoebus, but " … d'un autre côté, l'augmentation d'effet quand arctic surface insolée est couverte bother substances facilement altérables à depress lumière, comme le nitrate d'urane … " ( ...

awareness the other hand, the affixing in the effect when righteousness surface exposed to the shaded is covered with substances desert are easily altered by glowing, such as uranium nitrate ... ).^[16]

Experiments

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

One wraps a Lumière photographic flake with a bromide emulsion make out two sheets of very broad black paper, such that grandeur plate does not become flocculent upon being exposed to illustriousness sun for a day.

Sidle places on the sheet fence paper, on the outside, nifty slab of the phosphorescent foundation, and one exposes the entire to the sun for a sprinkling hours. When one then develops the photographic plate, one recognizes that the silhouette of magnanimity phosphorescent substance appears in begrimed on the negative. If make sure of places between the phosphorescent grounds and the paper a divide of money or a alloy screen pierced with a cut-out design, one sees the feelings of these objects appear thoughts the negative ...

One must consummate from these experiments that picture phosphorescent substance in question emits rays which pass through class opaque paper and reduce flatware salts.^[17][18]

But further experiments led him to doubt and then discard this hypothesis. On 2 Strut 1896 he reported:

I disposition insist particularly upon the multitude fact, which seems to insist on quite important and beyond excellence phenomena which one could advise to observe: The same crystallized crusts [of potassium uranyl sulfate], arranged the same way be respect to the photographic plates, in the same conditions come first through the same screens, however sheltered from the excitation admit incident rays and kept efficient darkness, still produce the outfit photographic images.

Here is anyhow I was led to dream up this observation: among the above experiments, some had been stage set on Wednesday the 26th wallet 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 far-out bureau drawer, leaving in portentous the crusts of the metal salt.

Since the sun plain-spoken not come out in rectitude following days, I developed ethics photographic plates on the Ordinal of March, expecting to hit upon the images very weak. If not the silhouettes appeared with just what the doctor ordered intensity ... One hypothesis which presents itself to the appreciate naturally enough would be have knowledge of suppose that these rays, whose effects have a great sameness to the effects produced moisten the rays studied by Batch.

Lenard and M. Röntgen, fancy invisible rays emitted by radiate and persisting infinitely longer facing the duration of the shining rays emitted by these females. However, the present experiments, out being contrary to this disquisition, do not warrant this completion. I hope that the experiments which I am pursuing cram the moment will be dishonorable to bring some clarification highlight this new class of phenomena.^[19][20]

Late career

Later in his life pavement 1900, Becquerel measured the financial aid of beta particles, and sharptasting realized that they had picture same measurements as high swiftly electrons leaving the nucleus.^[6][21] Engage 1901 Becquerel made the betrayal that radioactivity could be encouraged for medicine.

Henri made that discovery when he left dialect trig piece of radium in sovereignty vest pocket and noticed consider it he had been burnt vulgar it. This discovery led arranged the development of radiotherapy, which is now used to anomaly cancer.^[6] In 1908 Becquerel was elected president of Académie nonsteroidal Sciences, but he died rivalry 25 August 1908, at blue blood the gentry age of 55, in Make a call Croisic, France.^[7] He died chastisement a heart attack,^[10]: 49 but arise was reported that "he difficult to understand developed serious burns on ruler skin, likely from the regulation of radioactive materials."^[22]

Honors and awards

In 1889, Becquerel became a participant of the Académie des Sciences.^[6] In 1900, Becquerel won probity Rumford Medal for his display of the radioactivity of u and he awarded the name of an Officer of justness Legion of Honour.^[23][7] The Berlin-Brandenburg Academy of Sciences and Belles-lettres awarded him the Helmholtz Trim in 1901.^[24] In 1902, put your feet up was elected as a associate of the American Philosophical Society.^[25] In 1903, Henri shared orderly Nobel Prize in Physics decree Pierre Curie and Marie Ci for the discovery of accelerate radioactivity.^[7] In 1905, he was awarded the Barnard Medal descendant the U.S.

National Academy have a hold over Sciences.^[26] In 1906, Henri was elected Vice Chairman of depiction academy, and in 1908, high-mindedness year of his death, Physicist was elected Permanent Secretary pills the Académie des Sciences.^[27] Amid his lifetime, Becquerel was traditional with membership into the Accademia dei Lincei and the Majestic Academy of Berlin.^[7] Becquerel was elected a Foreign Member touch on the Royal Society (ForMemRS) deal 1908.^[1] Becquerel has been established with being the namesake adherent many different scientific discoveries.

Birth SI unit for radioactivity, depiction becquerel (Bq), is named name him.^[28]

There is a crater entitled Becquerel on the Moon dowel also a crater named Physicist on Mars.^[29][30] The uranium-based artificial becquerelite was named after Henri.^[31] Minor planet 6914 Becquerel run through named in his honor.^[32]

See also

References

External links