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he also found the radiometer!

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Niels Bohr: At the Crossroads of History

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Niels Henrik David Bohr was born on October 7, 1885, in Copenhagen, Denmark, to Christian

Bohr and Ellen Adler Bohr. His father was a physiology professor and his mother was the daughter of a wealthy Danish Jewish family. Niels was the second child of his parents. He had an elder sister – Jenny, and a younger brother – Harald. Niels was home-schooled until he was aged 7. After then, he began his formal schooling at the Gammelholm Latin School. The school was both an elementary and high school and observed strict discipline. The school expected its students to be disciplined and work hard. Niels' father, who was so passionate about his children's education, would bring home some of his fellow professors from the University of Copenhagen and allow his children to listen to their conversations, which encompassed arts, philosophy, and science.

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In 1903, aged 17, Niels attended the Copenhagen University where he studied mathematics, chemistry,
astronomy, but majored in physics under the tutelage of Professor Christian Christiansen.
While Niels was working towards his degree in 1905, the Royal Danish Academy of Sciences
announced to award the best research paper on methods for measuring the surface tension
of liquids with a gold medal. Though this prize was meant for experienced scientists,
Niels, still an undergraduate, decided to participate in the competition. He was ambitious
because of his growing strength and passion for physics.
He was allowed to use his father's physiology laboratory for his experiments and several
months, Niels worked tirelessly and obsessively, especially during the night. His father, worried
about his son's growing obsession with the experiments, ordered him to stop and focus
on his research. Niels left for his maternal grandparents' estate to continue his experiments.
He eventually completed the research and submitted it in late 1906. His research was sufficiently
brilliant and he won the gold medal – an incredible achievement for an undergraduate.
Niels then received his B.S. degree in 1907. In 1909, Niels earned his MSc. degree in physics.
He also went further to complete his Ph.D. in physics in 1911, both from the University
of Copenhagen. His doctoral dissertation was on the electron theory of metals.
In 1911, Niels was opportune to be among the few chosen to work in J. J. Thomson's Cavendish
Laboratory at the University of Cambridge in England. Niels arrived at the Laboratory
in October 1911. However, the 26-year-old Niels had a very bad start with Thomson. The
first thing Niels said to the Thomson was "this is wrong" pointing to a page in a book
written by Thomson. Niels also found it very hard to get along at the Cavendish Laboratory.
Niels conducted some research on cathode rays, but the research did not appeal to Thomson.
Towards the end of 1911, Niels met another great physicist, Ernest Rutherford, whose
lab was located at the University of Manchester. He asked if he could be transferred to Rutherford's
lab to work with him. Rutherford agreed but told him to seek Thomson's approval first.
The following year, Niels moved to Manchester to work with Rutherford and conduct his post-doctoral
research on the atomic structures. Niels soon became so interested in Rutherford's model
of the atom, which claimed that "the atom was made of a tiny, very dense, positively
charged nucleus surrounded by negatively charged electrons." And most especially in the behavior
of electrons, which was the subject of his doctorate thesis.
Niels and Rutherford eventually became greatest friends. Niels was not only inspired greatly
by Rutherford and his works, but both of them together with their wives spent happy vacations
together. In the fall of 1912, Niels returned to Denmark
with two foremost ideas: first, to better understand the behavior of electrons in the
atom and secondly, to pattern his behavior as a physicist after Rutherford's.
Niels married Margrethe Nørlund on August 1, 1912. Margrethe was a sister to the mathematician
Niels Erik Nørlund. The couple had six sons, but unfortunately, two of them died and only
four survived to adulthood. Only his son, Aage Bohr emulated him and won a Nobel Prize
in Physics. In 1913, Niels published a paper on atomic
structure. The paper formed the foundation for the famous "old quantum theory." Between
1914 and 1916, Niels was a lecturer of physics at the Victoria University of Manchester,
UK. In 1916, Niels was made a professor of theoretical
physics at the University of Copenhagen. He held this post for 46 years. In 1920, Niels
founded the "Institute of Theoretical Physics" at the University of Copenhagen and served
as the administrator of the institute for the rest of his life.
Niels was awarded the 1922 Nobel Prize in Physics for his research works on atomic structures.
He came up with more revolutionary theories. For instance, he collaborated with Werner
Heisenberg and other scientists on a new quantum mechanics principle, which was in connection
with his concept of complementarity. The concept of complementarity stated that "physical properties
on an atomic level would be viewed differently depending on experimental parameters." This
concept explains why light could be considered as either a wave or a particle, but not both
at the same time. During World War II and the reign of Adolf
Hitler, Niels was able to provide shelter to the German Jewish physicists at his institute
in Copenhagen, which caused many of the physicists to travel to the US. However, when Denmark
became occupied by Nazi forces, Niels and his family moved from Denmark to Sweden but
Niels and his son, Aage eventually fled to the United States. In the US, he worked on
the Manhattan Project in Los Alamos, New Mexico, where the first nuclear bomb was built. He
collaborated with the group of scientists who handle the research on nuclear fission
during the late 1930s. he actively contributed to "the liquid droplet" theory.
Due to Niels' concerns about how the nuclear bomb could be very destructive, he called
for active communication about using the nuclear weapon between nations and future international
arms control. This idea met was resisted by both Franklin D. Roosevelt and Winston Churchill.
After the World War, Niels returned to Europe and became an outspoken activist against the
use of nuclear weapons and for the peaceful application of atomic energy. In 1938, Niels
was made the President of the Royal Danish Academy of Sciences, where he supervised the
first phase of the Academy's program for the peaceful uses of atomic energy. In his open
letter to the UN in 1950, Niels envisioned an "open-world" mode of existence between
nations that abandoned isolationism for true cultural exchange.
In 1954, Niels actively participated in the launching of the European Organization for
Nuclear Research (CERN), a Europe-based particle physics research facility. He assembled the
"Atoms for Peace Conference" of 1955 and in 1957, he was awarded the "Atoms for Peace"
Award for his trailblazing theories and efforts to use atomic energy peacefully.
His personal research works led him to posit in a series of articles that atoms emit electromagnetic
radiation due to electrons jumping from an orbit level to a different one. This theory
was different from what was theorized by his friend and mentor Ernest Rutherford. Although
this discovery was later modified by later scientists, it formed the foundation for future
atomic research. Aside from his pioneering ideas, Niels was
well-known for his wit and warmth, as well as his humanitarian ethics. He was also a
prolific writer who authored over 100 publications. Niels suffered a stroke and eventually died
in 1962 at age 77. He died of sudden heart failure at his home in Carlsberg, Copenhagen,
Denmark. Niels' body was cremated, and his ashes were buried in the family plot in the
Assistens Cemetery in the Nørrebro section of Copenhagen.

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Dalton was born in England on the 6th of September 1766. He studied atomic structure and gave lectures presenting his research in Manchester. He discovered that the atoms are indivisible (can't be split) . He was also colour blind and tried to find out more about it through doing research on it.

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james chadwick!

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Who discovered neutron | James Chadwick | Discovery of neutron | Physic Topic

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In 1897 he proved that something called 'cathode rays' (radiation put out  when a voltage is applied between two plates made out of metal inside a glass tube with low-pressure gas) consists of particles that conduct electricity. These were electrons. Thomson also said that electrons are part of atoms.
He studied at the university of Manchester and at Trinity.

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He was a German chemist who studied similarities among specific elements. He also helped with the development of the periodic system of elements.

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He was a German chemist who studied similarities among specific elements. He also helped with the development of the periodic system of elements.

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He was a teacher and a chemist. He figured out and divided the periodic table — a system for classifying the  elements. He was also from Russia

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He was a teacher and a chemist. He figured out and divided the periodic table — a system for classifying the  elements. He was also from Russia

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He managed to discover the accurate determination of the charge carried by an electron. He also proved that the quantity of something is a constant for electrons.

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Britannica.com
Youtube
Nobelprize.org
Atomic Archieve
Famous scientists.org
Sheet/project done in class
Study.com
Lindahall.org
Aps.org
Royalsocietypublishing.org

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Boyle was born in Limerick in 1627, but also lived in England. He first studied at Eton College where he gained a love for knowledge. In 1639 he travelled around the continent to enhance his knowledge. In 1644 he returned to England and became a writer. In later years he grew an interest in nature and studied it through experimentation. He fell in love with performing scientific experiments and the knowledge that he gained from it. He became a natural philosopher and joined a sort of organisation called the 'Hartlib Circle'. In 1654 he was invited to study at Oxford University, where he could use their amazing and advanced technology to further study chemistry. There he joined a different group called the 'Experimental Philosophy Club'. Boyle, along with the help from this group(particularly a man named Hook), discovered a new scientific law, and called it 'Boyle's Law'. This law states that the amount/volume of gas (kept at a constant temperature) varies wit the amount of pressure exerted onto it. Like how our lungs expand when we breathe in more air.

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In early 1793 John accepted a post as a lecture of natural philosophy and mathematics at new college a dissenting institution that provided jobs religious candidates who had higher education in Manchester England that same year he published his first book based on his observations of meteorological subjects which were called meteorological observations and essays this book then became the foundations of the discoveries he would publish later in his life even though at the time other scholars paid little attention to it by the next year John wrote his first scientific paper known as extraordinary facts relating to the vision of colors which became the first write-up on the issue of color blindness or call a perception of the eye at a time John thought that the condition was hereditary as both he and his family members suffered from it John's theory was in fact wrong but because he was the first person to study the condition along with his thorough and methodical study of the condition which became widely recognized it was sim called dr. Nason but John was just getting started he published more scientific papers in the area of physical sciences covering topics like light properties

conduction of heat meteorology gas expansion by heat and even the aurora borealis by 1800 new college ran into financial difficulties and John resigned from his role as a lecturer choose

instead to work as a private teacher of mathematics and science in that same year John participated in an oral presentation on the details of his experiments on gases and the nature and composition of air as they related to atmospheric pressures the presentation

was titled experimental essays in 1801 John proposed the theory that became known as a dalton's law of partial pressures or more simply as dalton's law and which is still being used by practically every chemistry university students as well as scuba divers today to measure the level of pressure and their effects on nitrogen and air levels at different depths of the ocean throughout that same year in Manchester John gave a series of groundbreaking

presentations though the contents weren't published until 1802 in those presentations John once again presented his studies into liquids and gases and it gave insights into the nature of

gases the statements he made about the fact that when the volume of a gas is held constant in a container the pressure varies in direct proportion to its temperature this bold statement was

published a few years later in 1809 and was referred to as the gay lussac's law after the man who published it Joseph Gay Lusaka by this point in time John's work had distinguished him as a first rank scientist but it still came as a bit of a surprise when he was invited to give presentations at the Royal Institution in London despite his Quaker background John had beat all odds with his hard work and dedication until he was recognized by the very institutions that had rejected him long ago throughout his life John remained a faithful Quaker and was unmarried with no children in 1810 he was invited to become a member of the Royal Society but he declined in the early 1800s.

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John was awarded the society's royal

medal at the age of 71 john experienced

a slight stroke but recovered one year

later he suffered a more severe one that

affected his speech such that he

couldn't speak clearly. Five

years there after ,in 1844, John suffered from

another stroke that unfortunately killed him.

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Sir Humphrey Davy the cornish chemist and inventor who is best remembered today for his work on the isolation of iodine and the development of his famous miners safety lamp humphrey davy was one of the most brilliant scientists of the 19th century as a young apprentice to an apothecary he developed an interest in chemistry his first post was at the pneumatic

institution in bristol where he studied the effects of nitrous oxide commonly known as laughing gas in 1801 he was appointed to the royal institution as director of the laboratory and

assistant chemistry lecturer between 1802 and 1812 he was professor of chemistry here his work established the science of electrochemistry and he isolated potassium sodium magnesium barium

strontium and calcium by electrolysis he also carried out research into the tanning industry and agricultural chemistry as well as observing the electrical arc he was knighted in 1812 and in 1813 he appointed a book binders apprentice michael faraday as his scientific assistant faraday of course would go on to become one of the most important and influential scientists in history

Davey toured the continent between 1813 and 1815 with faraday the IIT archives hold some of faraday's notebooks from this period and these describe his travels in europe davey's later successes included the isolation of iodine the development of his famous minor safety lamp and his appointment as president of the royal society in the 1820s he advised the admiralty on how to protect the bottom of their ships and also worked on improving optical glass in 1818 davey was awarded the baronetcy this was at the time the first such honour ever conferred on a man of science in Britain sadly his health began to decline and he suffered a serious stroke while in switzerland in 1929 he died that same year in geneva davey is commemorated with a tablet in

westminster abbey and a towering legacy as one of the greatest scientific minds.

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He grew up in the poorest of circumstances on the Bug manor before he was able to start his pharmacist apprenticeship in Münchberg at the age of 14. As a provisional in the deer pharmacy in Strasbourg, he worked as a scientific autodidact on his further education and also made a name for himself as a writer. Returning home in 1802, he failed to establish himself as a pharmacist. A drug and local product store he founded in Gefrees was officially closed to him because of "bungling". He then joined his brother-in-law's cotton business in Münchberg, where he oversaw the dyeing and bleaching works, but the consequences of the Continental System made the business unprofitable. Eventually he became brewery administrator in Sankt Johannis near Bayreuth, but the estate was sold and the brewery and distillery were closed. That's how it turned outD. and his family were in dire straits when, in 1810, the "Professor Doctor Wolfgang Doebereiner zu Sankt Johannis bei Bayreuth" was appointed associate professor of chemistry, pharmacy and technology at the was delivered to the University of Jena. D. , the man from the people who had never been able to study, held this position of academic teacher as an internationally respected researcher until his death. The Jena doctoral diploma was awarded to him by the philosophical faculty on November 30, 1810, since the previous publications D.s "already unmistakably carried the stamp of ingenuity and perfection". Despite all the conventional forms, a close personal connection soon developed with Goethe. Goethe did everything possible to gradually improve D. 's inadequate salary, teaching and living conditions and to constantly promote his chemical institute. “Goethe gave and took, while Döbereiner took and gave vice versa” (Dissinger). The Duke was pleased about D. 's efforts to always put the substrate of knowledge into practice. Dwas responsible for the supervision of breweries, distilleries and other branches of industry in the early years. In 1812, for example, he set up a small starch sugar factory in Tiefurt, and in 1816 he carried out gas experiments to produce “the cheapest and purest fuel gas” (our modern “water gas”) from coal and water at high temperatures. Out of gratitude for Carl August, D. turned down later appointments to Bonn, Halle, Munich, Würzburg and Dorpat - the last one associated with the hereditary title of nobility and a high salary.

D. is one of the chemists who tried to demonstrate the generality of the stoichiometric laws recognized by KF Wenzel and JB Richter. However, this also led him to study the stoichiometrically inexact chemical processes that J. von Berzelius summarized in 1835 under the term catalysis. As early as 1808 D. studied the influence of the acid concentration on starch saccharification, and in 1816 the formation of formic acid when tartaric acid was oxidized with manganese dioxide. Above all, D.to the study of the catalytic action of platinum metals. In 1816 he succeeded in oxidizing the alcohol to acetic acid in the cold with the help of platinum black, which led to a process for the production of rapid vinegar. In 1823 he succeeded | the instantaneous ignition of an oxyhydrogen mixture using a platinum sponge; the all-worldly exciting discovery led to the large-scale production of the so-called D.schen platinum lighter (in 1827 the "fragrance lamp"). Further catalytic discoveries are the production of fuming sulfuric acid from a mixture of sulfur dioxide and oxygen using hygroscopically moist platinum black (later called "contact sulfuric acid") and the realization that the effect of platinum can be increased by moistening it with weak potassium hydroxide solution. He also expressed the ingenious idea of ​​a catalytic synthesis of sugar from alcohol vapor and carbon dioxide. With the observation (1824) that oxyhydrogen cannot be caused to explode by iridium alone, but by iridium with the addition of osmium, D. became the creator of the mixed catalysts, which are now indispensable in modern large-scale chemical industry. He was also the first to introduce microchemical reactions in the aqueous phase. Dalways strived for the knowledge of an order, a natural system of the elements. In 1817 he began to “group materials according to their analogy”. He found groups of three (“triads”) in which the atomic weight of the middle element is approximately the arithmetic mean of the atomic weights of the two outer ones. He succeeded in predicting the atomic weight of bromine, which was not yet precisely determined, and in changing the atomic weight of iridium.

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Mendeleev was born in Siberia, in 1834

as the youngest of between eleven and seventeen siblings.

No one is quite sure, this is just—this is a bad lot in life. And he almost died as a teenager of tuberculosis.

But lucky for us, he survived, and also lucky for us, his mom put all of her faith into this one child

and sent him to Saint Petersburg to study and become a scientist.

He went on to become a professor in Saint Petersburg,

his dissertation was called "On the Combinations of Water and Alcohol"

and I know that sounds really boring, but it's going to come in handy.

Between 1868 and 1870 was when Mendeleev was writing his seminal work, "The Principles of Chemistry"

and that's when he came up with his most influencial idea, the Periodic Law.

The theory was, that if you arranged elements by similar properties and by atomic weight,

they would appear periodically, in rows. This may sound familiar.

He illustrated this in the rudimentary, but revolutionary, periodic table of all known elements at the time,

there were about sixty, and it looked like this.

Not exactly what's hanging in your chemistry class, but if you flip it ninety degrees,

you can see the origins of the periodic table of the elements.

Just one of the amazing things about Mendeleev's discovery here is that

he discovered it 25 years before the discovery of the electron.

At the time, everyone in the world of science knew that the atom was the most basic particle. So determining the weight of an element basically consisted of figuring out how heavy it was compared with the lightest element, which was hydrogen. Still is hydrogen. Only later would scientists figure out a more precise measure, the atomic weight, which takes into account the protons, neutrons and the electrons in the atom.

But here's what I like most about Mendeleev, not only did he arrange electrons by their atomic weight, anybody can do that, but he also spotted holes in the table and he theorized that those atoms, those elements, would be discovered some day.

And he postulated, like, with enormous accuracy the properties of those elements.

Of the ten elements Mendeleev predicted in his first table, seven were eventually discovered. This achievement quickly won Mendeleev some clout, including some clout in his personal life. In the 1880s, Mendeleev became obsessed with his niece's best friend, and he threatened to kill himself unless she married him. The problem was, that he was already married. So he divorced his first wife and married his niece's friend,

which according to the Russian Orthodox Church was bigamy. When critics accused Mendeleev of this moral crime, Tsar Alexander reportedly said, "Well, Mendeleev has two wives, but I only have one Mendeleev." With the Tsar on his side, he was then made the Director of the Bureau of Weights and Measures, where his job was to come up with the official standards for the production of vodka. Thanks to him, all russian vodka to this day has to be exactly 40 percent alcohol.

He also pioneered the study of petroleum and helped found Russia's first oil refinery.

Probably the only exports Russia has now, that this guy didn't help with are caviar and hip-hop polka. In 1906 Mendeleev was nominated for a Nobel prize for his Periodic Law,

but he had managed to aggravate an influential Swedish chemist Svante Arrhenius

by publicly criticizing some of Arrhenius' theories. The Swede returned the favor by lobbying hard against him on the Nobel committee and he was denied the prize.

Mendeleev died the following year of influenza, having mastered the elements and petroleum and alcohol and even bigamy. He didn't get the Nobel prize but in the end he did get an even more prestigious scientific honor and that is having a chemical element named after him. It's one of the new synthetic ones and yes, it's super radioactive. It's called mendelevium.

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Who was Robert Millikan?  Robert
Milligan was an American scientist u.s.
professor at the University of Chicago
not only did he co-authored many
textbooks and he also revolutionized
atomic science with the now famous
oil-drop experiment let's go
first, the atomizer sprays a fine mist of
oil into the upper chamber some droplets
fall through the holes in the upper
chamber and continue to fall until they
reach terminal velocity using this
microscope Millikan can measure their
velocity using a special formula
calculating the mass of a negative charge
was applied to the falling drops by
applying radiation to the bottom chamber
this created an electric field between
the two plates which counteracted
gravity and called the oil droplet to
hang in midair the mass of the suspended
drop equals the product of the electric
field and the charge and that's how
Robert Millikan calculated the charge of
an electron
dude that experiment was awesome
that's Posterous didn't even include all
the data in the scientific reports you
know commercial that was some people
even say that you shouldn't have
received the Nobel Prize in 1923 did not
cool he was an essential scientist
of the nineteen hundreds okay then look
back here in an excellent experiment
by ignoring it
so what you're saying and that his
conclusion was invalidated
because he forgot to write everything
down he didn't forget anything you just
wanted to reduce the margin of error
from 10% up to 2.5 percent

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On August 30, 1871, Ernest Rutherford was born to James in Spring Grove, New Zealand.
Rutherford, Scottish coachbuilder and engineer, and Martha Rutherford, English school
Teacher. Ernest Rutherford grew up in a large family; He was the fourth child in a family of 12
sons

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At McGill, Rutherford discovered radon, a chemically unreactive but radioactive gas.
later he showed that some heavy atoms spontaneously decay into slightly lighter atoms;
hence the discovery of radioactive decay. In 1904 Rutherford published his first book, Radioactivity
In 1908, he was awarded the Nobel Prize in Chemistry for his research on disintegration.
elements and chemistry of radioactive substances” . Ever since Rutherford realized lead was the end product of uranium decay, was able to suggest the rate of uranium decay atoms that would allow mineral dating . Rutherford moved to the University of Manchester in 1907.The molecule he had discovered earlier was a helium atom with no electrons . During his stay inMcGill, Rutherford observed that a narrow beam of alpha particles blurred as they passed through it. By a thin layer of mica. With this information, Rutherford hired his assistant Hans Geiger to measure the relative number of alpha particles as a function of angular scattering. Geiger chose Ernest Marsden to help study alpha scattering and discovered that some alpha rays were scattered back, even from a thin layer of gold.
Surprised, Rutherford said: "It was as if a man had thrown a large shell at a piece of cloth.
paper and came back” . This experiment later became known as gold foil.
to experiment. In 1911, at the age of 40, based on these results, he proposed that almost all the masses
an atom is concentrated in a nucleus that is a thousand times smaller than the atom itself.
This was the first project of the nuclear model of an atom.

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Local chemist John Newland was the first to compile a table of chemical elements arranged according to their relative atomic masses. Born in Elephant and Castle Newlands, he is one of three great 19th century scientists associated with our area. Although less well known than his contemporaries Michael Faraday and Charles Page, Newlands was a major figure in British science.
John Alexander Raina Newland was born just four months after Queen Victoria's accession to the throne. He was born on November 26, 1837 in the West Square, just behind the Bethlehem Hospital, where the Imperial War Museum is today.
In his early years, John was homeschooled, usually with his father, Presbyterian minister Fr. William Newland. At 19, he entered the Royal College of Chemistry - the first constitutional department of Imperial College London - to study with August von Hoffmann, the German chemist who discovered formaldehyde and helped establish the synthetic dyes industry. He later transferred to the Royal Agricultural Society.

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He divided the elements into seven groups of eight, which he later called the "rule of the octave." He admitted that his table was incomplete and considered the possibility of unknown pieces. It contained elements that were later identified, such as the germanium that he himself predicted.
Unfortunately, there were bugs and anomalies in the Newlands tables. In particular, he reformulated some of the commands to make the "octaves" clearer. For many years this caused the academic establishment to forget the importance of his achievements, and neither the Chemical Society nor the Royal Society published his work.
However, in the late 1960s, work by Dmitri Mendeleev and Lothar Meier (more precisely) on the arrangement of elements appeared in Britain. This led to Newland gaining more recognition. His efforts were finally rewarded when the Royal Society awarded him the Davy Medal in 1887 for his outstanding research in chemistry.