Niels Bohr, John Dalton, And Earnest Rutherford

As scientists started researching atoms, many had different ideas on what was actually going on inside the atoms and what the atoms looked like. A few of these scientists were Niels Bohr, J.J. Thompson, John Dalton, and Earnest Rutherford. These four men defined what atomic theory was with all the research and experiments they did. They each came up with ideas about atoms. John Dalton: John Dalton was born September 6, 1766. Dalton’s father worked as a weaver, his father owned a small plot of land and a small house, Dalton’s parents were both Quakers. John grew up in the Victorian times in England, as a child Dalton was very intelligent noticing fine details and gathering information very well. He attended a small village school until the
age eleven, then he started helping as a teacher. At the age of fifteen John and his brother moved forty miles away from home to start a boarding school together, John became the principal of the school, and while he was working there he continued teaching himself science, math, Latin, Greek, and, French. At the age of twenty-six Dalton took a job teaching mathematics and natural philosophy at a college in Manchester. While teaching here he wrote his first scientific paper called the Extraordinary Facts Relating to The Vision Of Colours. This paper discussed color blindness, Dalton realized it was a hereditary trait because he and members of his family had it. Dalton's theory about colour blindness was wrong, But he was the first person to research it, so from then on it was called Daltonism. In the 1800’s, Dalton became a tutor, and resigned from the college which was having financial difficulty. Experiments: Dalton did tests and found that 12 grams of carbon could react with 16 grams of oxygen to form the compound we now call carbon monoxide, or with 32 grams of oxygen to form carbon dioxide. Then he realized that the ration 32:16 was equal to 2:1 which intrigued him and inspired him to do more experiments. Dalton’s most notable experiment is when he found that gases could be liquefied, he stated that when its volume is held constant in a container, then the pressure of gas varies in direct proportion. Atomic Theory: Dalton’s experiments on gases led him to find that every form of matter was also made up of small individual particles.
Dalton used the Greek word “atomos” or “atoms” to label the particles. Dalton believed that atoms of different elements could be distinguished based on their varying atomic weights, While doing this, he became the first scientist to explain the behavior of atoms using the measurement of weight. Dalton also the first scientist to discover that atoms could not be created or destroyed. J.J. Thompson: J.J. Thompson was born December 18, 1856. J.J.’s father was a book seller who planned on J.J. being an engineer. J.J. attended Owens college and received a minor Scholarship to attend Trinity college at Cambridge and study mathematics. After graduation J.J. worked in the Cavendish laboratory. He quickly earned a membership in the prestigious royal society and became the professor of physics at the age of 28. He was respected and students came from around the world to study with
him.
Experiments: In 1894, J.J. started studying cathode rays. Cathode rays were a popular test subject because the nature of cathode rays was unclear. Thompson used better equipment and methods than had been used in the past. He was able to calculate the angle at which the rays went through the vacuum tube and calculate the ratio of the electrical charge to the mass of the particles. He was able to discover that the ratio was the same regardless of the type of gas used, which allowed him to discover that the particles are the same in all gases. Thompson called particles ‘corpuscles’ although we now call them electrons. Thompson’s most notable experiment was when he channeled a stream of ionized neon through a magnetic and electric field and used deflection techniques to measure the charge to mass ratio. Thompson confirmed that neon is made up of two different kinds of atoms, and proved existence of isotopes in a stable element. This was the first time someone had used mass spectrometry. Atomic Theory: J.J.’s atomic theory was that the atom was made up of small particles called electrons. He proved this theory using the cathode ray tube. Running rays through the tube and measuring the ratio of ray and electricity, this helped Thompson conclude his answer to what was inside an atom. Ernest Rutherford: Ernest Rutherford was born August 30, 1871.
Rutherford was the fourth of 12 children, and the second son. His father had little education and struggled to support the large family. His mother worked as a school teacher, she believed knowledge is power and put a strong emphasis on her children's education. Ernest spent most of his time milking cows and doing other chores on the farm. Rutherford was given his first science book at the age of ten and it inspired his first experiment. He constructed a miniature cannon, which exploded. Rutherford was very smart and loved school. In 1887 he was awarded a scholarship to Nelson Collegiate School, a private secondary school. In 1890, Rutherford received another scholarship, this time to Canterbury College in Christchurch, New Zealand. While Rutherford was attending Canterbury, his professor encouraged Rutherford to find concrete proof through scientific experiments. Rutherford managed to achieve first class honors in math and science. Rutherford conducted independent research on high frequency electrical discharges ability to discharge a magnet. After earning a Bachelors degree in science, he fell in love with his landlady’s daughter, Mary Newton. They were married in 1900, and had a daughter 1 year later named
Eileen. Experiments: Rutherford most notable experiment was about uranium’s reaction to tin foil, when doing tests Rutherford discovered that one type of uranium was soaked up easily by the tin foil but another type had no trouble penetrating the foil. Some other experiments Rutherford did were on x-rays. Rutherford studied what the effects were on conductivity of gases, resulting in a paper on splitting atoms and molecules into ions. Rutherford worked with J.J. Thompson to accomplish these feats. After moving back to Manchester, Rutherford made an astonishing discovery that an atoms weight was almost all made up by the nucleus. In doing so, he created a nuclear model, a discovery that paved the way to the invention of the atom bomb. Named “The Father Of The Nuclear Age” Rutherford was awarded the Nobel Prize for chemistry in 1908. After this, Rutherford focused on anti-submarine research, though nuclear reactions were his focus for the rest of his career. Atomic Theory: Ernest Rutherford’s atomic theory was that in an atom there is a nucleus. He also believed that the nucleus is what makes up most of the atom and was the heaviest part of the atom. Rutherford was able to discover this by firing alpha particles at foil. Rutherford’s experimentation allowed him to create a nuclear model. Niels Bohr: Niels Bohr was born October 7, 1885. His mother was part of a Jewish banking clan, and his father, a celebrated physiology academic. Niels attended Copenhagen University, where he received his masters and doctorate in physics. Niels was soon married to Margrethe Norlund; the couple had six children, four who would survive to adulthood. Niels theorized that atoms give off electromagnetic radiation. Though these theories would be tweaked by other scientists, they would be the basis for atomic research. Niels received the Nobel Prize for physics in 1922, for his work on atomic structures. Niels was known for his wit, and his humanitarian ethics. Experiments: Bohr’s most notable experiment was when he was researching nuclear fission, with other scientist’s, Bohr contributed his liquid droplet theory. This helped the scientists research nuclear fission, and led to future concepts in nuclear research. Atomic Theory: Bohr’s atomic theory is that in an atom, the electrons spiral around the nucleus, gaining and losing energy with each spiral, thus making a never ending energy source. Bohr also believed that the electrons were on fixed courses revolving around the nucleus, and the electrons could hop between orbits. Conclusion: In conclusion, these four scientists paved the path to nuclear studies and research. Bringing theories and proven facts to the world of science and applying things other people would not have thought of. Each of these scientists brought something of their own and as the years progressed they built off of each others work. Because of these four men and many others, the world is changed forever.