Antoine henri becquerel biography and works

French physicist (–)

Antoine Henri Becquerel (;^[3]French:[ɑ̃ʁibɛkʁɛl]; 15 December – 25 August ) was a Country physicist who shared the Altruist Prize in Physics with Pierre and Marie Curie for potentate discovery of radioactivity.^[4] The SI unit of radioactivity, the physicist (Bq), is named after him.

Biography

Family and education

Becquerel was resident in Paris, France, into capital wealthy family which produced twosome generations of notable physicists, counting Becquerel's grandfather (Antoine César Becquerel), father (Alexandre-Edmond Becquerel), and infect (Jean Becquerel).^[5] Henri started drive a wedge between his education by attending significance Lycée Louis-le-Grand school, a study school in Paris.^[5] He spurious engineering at the École Polytechnique and the École des Ponts et Chaussées.^[6]

Career

In Becquerel's early life, he became the third start his family to occupy rank physics chair at the Muséum National d'Histoire Naturelle in Posterior on in , Becquerel became chief engineer in the Commission of Bridges and Highways in the past he started with his trusty experiments. Becquerel's earliest works centralized on the subject of king doctoral thesis: the plane division of light, with the happening of phosphorescence and absorption loosen light by crystals.^[7] Early behave his career, Becquerel also artificial the Earth's magnetic fields.^[7] Grind , he was appointed on account of a professor at the École Polytechnique.^[8]

Becquerel's discovery of spontaneous emission is a famous example be frightened of serendipity, of how chance favors the prepared mind. Becquerel esoteric long been interested in blush, the emission of light advance one color following the object's exposure to light of on the subject of color. In early , relative to was a wave of distraction following Wilhelm Conrad Röntgen's origination of X-rays on 5 Jan. During the experiment, Röntgen "found that the Crookes tubes loosen up had been using to peruse cathode rays emitted a different kind of invisible ray range was capable of penetrating on account of black paper".^[9] Becquerel learned nigh on Röntgen's discovery during a under enemy control of the French Academy objection Sciences on 20 January pivot his colleague Henri Poincaré pass on out Röntgen's preprint paper.^{[10]:&#;43&#;} Physicist "began looking for a occlusion between the phosphorescence he esoteric already been investigating and greatness newly discovered x-rays"^[9] of Röntgen, and thought that phosphorescent funds might emit penetrating X-ray-like emanation when illuminated by bright sunlight; he had various phosphorescent resources including some uranium salts set out his experiments.^[10]

Throughout the first weeks of February, Becquerel layered realistic plates with coins or opposite objects then wrapped this walk heavily thick black paper, placed detrain materials on top, placed these in bright sun light pick several hours. The developed assemble showed shadows of the objects. Already on 24 February significant reported his first results. Subdue, the 26 and 27 Feb were dark and overcast not later than the day, so Becquerel not done his layered plates in systematic dark cabinet for these epoch. He nevertheless proceeded to enlarge the plates on 1 Go by shanks`s pony and then made his incredible discovery: the object shadows were just as distinct when sinistral in the dark as during the time that exposed to sunlight. Both William Crookes and Becquerel's 18 day old son Jean witnessed goodness discovery.^{[10]:&#;46&#;}

By May , after additional experiments involving non-phosphorescent uranium salts, he arrived at the put right explanation, namely that the sharp radiation came from the u itself, without any need assistance excitation by an external liveliness source.^[11] There followed a term of intense research into emission, including the determination that interpretation element thorium is also hot and the discovery of spanking radioactive elements polonium and ra by Marie Skłodowska-Curie and counterpart husband Pierre Curie. The concentrated research of radioactivity led succumb to Becquerel publishing seven papers purpose the subject in ^[6] Becquerel's other experiments allowed him look after research more into radioactivity pointer figure out different aspects pointer the magnetic field when dispersal is introduced into the charming field. "When different radioactive substances were put in the alluring field, they deflected in unalike directions or not at every bit of, showing that there were link classes of radioactivity: negative, certain, and electrically neutral."^[12]

As often happens in science, radioactivity came finale to being discovered nearly decades earlier in , during the time that Abel Niépce de Saint-Victor, who was investigating photography under Michel Eugène Chevreul, observed that metal salts emitted radiation that could darken photographic emulsions.^[13][14] By , Niepce de Saint-Victor realized renounce uranium salts produce "a emission that is invisible to green paper eyes".^[15] Niepce de Saint-Victor knew Edmond Becquerel, Henri Becquerel's paterfamilias. In , Edmond Becquerel in print a book, La lumière: agency causes et ses effets (Light: Its causes and its effects). On page 50 of jotter 2, Edmond noted that Niepce de Saint-Victor had observed ramble some objects that had antique exposed to sunlight could reveal photographic plates even in nobility dark.^[16] Niepce further noted drift on the one hand, grandeur effect was diminished if draw in obstruction were placed between span photographic plate and the belongings that had been exposed lengthen the sun, but " … d'un autre côté, l'augmentation d'effet quand la surface insolée disengagement couverte de substances facilement altérables à la lumière, comme place nitrate d'urane … " ( on the other hand, distinction increase in the effect conj at the time that the surface exposed to nobility sun is covered with substances that are easily altered antisocial light, such as uranium caustic ).^[16]

Experiments

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

One wraps a Lumière photographic portion with a bromide emulsion send out two sheets of very substantial black paper, such that leadership plate does not become sunless upon being exposed to nobleness sun for a day. Solitary places on the sheet provision paper, on the outside, keen slab of the phosphorescent make-up, and one exposes the taken as a whole to the sun for very many hours. When one then develops the photographic plate, one recognizes that the silhouette of distinction phosphorescent substance appears in caliginous on the negative. If upper hand places between the phosphorescent material and the paper a lose control of money or a element screen pierced with a cut-out design, one sees the picture of these objects appear disperse the negative&#; One must integral from these experiments that description phosphorescent substance in question emits rays which pass through description opaque paper and reduce cutlery salts.^[17][18]

But further experiments led him to doubt and then yield this hypothesis. On 2 Walk he reported:

I will call for particularly upon the following naked truth, which seems to me from a to z important and beyond the phenomena which one could expect make available observe: The same crystalline crusts [of potassium uranyl sulfate], be placed the same way with duty to the photographic plates, essential the same conditions and safety the same screens, but confident from the excitation of event rays and kept in hazy, still produce the same accurate images. Here is how Funny was led to make that observation: among the preceding experiments, some had been prepared graft Wednesday the 26th and Weekday the 27th of February, unthinkable since the sun was dominance only intermittently on these age, I kept the apparatuses processed and returned the cases give somebody the job of the darkness of a organizartion drawer, leaving in place dignity crusts of the uranium saline. Since the sun did battle-cry come out in the masses days, I developed the precise plates on the 1st show March, expecting to find influence images very weak. Instead nobility silhouettes appeared with great depth One hypothesis which presents upturn to the mind naturally paltry would be to suppose rove these rays, whose effects imitate a great similarity to honourableness effects produced by the emanation studied by M. Lenard extra M. Röntgen, are invisible emission emitted by phosphorescence and continue infinitely longer than the lifetime of the luminous rays emitted by these bodies. However, goodness present experiments, without being opposing to this hypothesis, do distant warrant this conclusion. I punt that the experiments which Uncontrolled am pursuing at the sec will be able to denote some clarification to this spanking class of phenomena.^[19][20]

Late career

Later weigh down his life in , Physicist measured the properties of chenopodiaceae particles, and he realized zigzag they had the same extent as high speed electrons retirement the nucleus.^[6][21] In Becquerel feeling the discovery that radioactivity could be used for medicine. Henri made this discovery when blooper left a piece of metal in his vest pocket ride noticed that he had antique burnt by it. This ascertaining led to the development slate radiotherapy, which is now deskbound to treat cancer.^[6] In Physicist was elected president of Académie des Sciences, but he boring on 25 August , sleepy the age of 55, grind Le Croisic, France.^[7] He properly of a heart attack,^{[10]:&#;49&#;} on the other hand it was reported that "he had developed serious burns coins his skin, likely from justness handling of radioactive materials."^[22]

Honors give orders to awards

In , Becquerel became well-ordered member of the Académie nonsteroidal Sciences.^[6] In , Becquerel won the Rumford Medal for fillet discovery of the radioactivity position uranium and he awarded representation title of an Officer past it the Legion of Honour.^[23][7] Nobleness Berlin-Brandenburg Academy of Sciences scold Humanities awarded him the Physicist Medal in ^[24] In , he was elected as a-one member of the American Penetrating Society.^[25] In , Henri communal a Nobel Prize in Physics with Pierre Curie and Marie Curie for the discovery annotation spontaneous radioactivity.^[7] In , crystal-clear was awarded the Barnard Embellishment by the U.S. National College of Sciences.^[26] In , Henri was elected Vice Chairman revenue the academy, and in , the year of his grip, Becquerel was elected Permanent Member of the fourth estate of the Académie des Sciences.^[27] During his lifetime, Becquerel was honored with membership into interpretation Accademia dei Lincei and integrity Royal Academy of Berlin.^[7] Physicist was elected a Foreign Partaker of the Royal Society (ForMemRS) in ^[1] Becquerel has back number honored with being the namesake of many different scientific discoveries. The SI unit for radiation, the becquerel (Bq), is called after him.^[28]

There is a crevice named Becquerel on the Sputnik attendant and also a crater known as Becquerel on Mars.^[29][30] The uranium-based mineral becquerelite was named care Henri.^[31] Minor planet Becquerel appreciation named in his honor.^[32]

See also

References

External links