Volume 1
Issue 4
November, 2013
By Brandie Joy and Steve Swarts Do you know how the nucleus was discovered? Or who discovered it? Well you’re in luck, because we do! IN 1911 a New Zealand man named Ernest Rutherford was trying to verify that the plum pudding model was still right by using new technology. One way experimented using the gold The way he
Rutherford this theory was foil experiment. conducted this
experiment zinc coded
was he had a screen that
flashed a light
every time it got
hit by a showed that
particle. It particles didn’t
just go through the nucleus (the gold foil in the middle of the circle of zinc) like he thought it would but it ricishaded off in different directions. Rutherford chose gold foil and zinc because he knew that different elements on the periodic table are heavier than others, which means the atomic number differs. Rutherford’s theory was right because it proved that the plum pudding model was not 100% correct, because the fact that the particles didn’t go straight through the nucleus they bounced off into different directions.
By: Chudier Yien, Wendy Robles November, 2013
Niels Bohr discovered the planetary model in 1913. He did this by passing a light through a glass tube that contained hydrogen and it gave off a certain color schemes. The fact that hydrogen atoms absorb radiation at a limited number of frequencies suggests that these atoms can only absorb radiation with certain energies. This suggests that there are only a limited number of energy levels within the hydrogen atom. These energy levels are countable. Electrons are not able to lose energy otherwise they would be spiral in towards the nucleus. The significance of his experiment is that he discovered electrons orbit around the nucleus, with lower energy electrons closest to the nucleus and higher energy ones further away. This made a path for other scientist to improve on. Bohr’s experiment impacted society by discovering electrons orbited around the nucleus.
By Cody Park & Nic Snider
November, 2013
James Chadwick was an English scientist that did most of his work in the mid 1900’s. What made him a notable scientist of the 1900’s was his discovery of the neutron. He saw holes in Rutherford’s theory. Rutherford wasn’t necessarily wrong but he wasn’t completely correct either. Rutherford discovered the nucleus was composed of protons but he thought that that was all that it was composed of. These elements had atomic mass and when you added the mass of the electrons and the mass of the protons it didn’t add up. Chadwick realized that atoms were composed of more than just electrons and protons. What Chadwick did was he shot alpha particles at wax and noticed that the charge was the same but the alpha particles lost their mass. This told him that there was something more in the nucleus. This was the discovery of the neutron. The discovery of the neutron was one of the most significant discoveries of the 20th century because it is an essential component of the atom.
By: Colton Preston and Lexi Teel In 1915 Niels Bohr did an experiment to help define the electron location and the energy of the electron in an atom. In his experiment he used colors to match up the electrons based on which electron path they followed. This experiment was very influential in the creation of the atomic model because it stated that electrons followed on different paths that rotated around the nucleus. Bohr’s Theory is a theory that is still in effect today. In the current atomic model there are still different layers that the electrons flow on which directly came from Bohr’s model. Quantum Mechanics -The laws of physics that describe the interactions of very small (atomic or subatomic) objects, also known as "wave mechanics" and "quantum physics".
Although Bohr's Theory is used in today’s atomic model there were some holes in his experiment and his conclusion. One of the bigger problems with Bohr’s experiment is that it violates the Heisenberg Uncertainty Principle because Bohr inferences that electrons have both a known radius and orbit. Also it makes poor inferences regarding the spectra of larger atoms. Although there are some holes with his experiment was very influential in the creation of the atomic model and Quantum Mechanics.
By: Selma Becirovic and Dominique Mullins Gold 1
such as helium nuclei pass through a barrier. barrier the particle charge yet less mass, was something in this charge but had mass.
James Chadwick, an English physicist, discovered that the neutron had no charge at all. Chadwick studied under Ernest Rutherford in Cambridge; this is where he would do the experiment that changed science today. He used scattering data to calculate the mass of this neutral particle, his main experiment that is known today would be where he took particles that had alpha rays which has a charge, and had it After it passed through the came out with the same he then discovered that there particle’s nucleus that had no He discovered the neutron.
Chadwick’s discovery of the neutron was almost perfect; he of course had a few minor mistakes such as, what he believed to be the size of the neutron was not correct, it did not have the same amount of mass he thought it had either. If not for Chadwick’s discovery, society today would not know about what a neutron was and could possibly still have been thinking that Rutherford’s theory was correct. Chadwick’s experiment was a breaking point in the research of the atom, this being said, it may be one of the biggest discoveries in the history of science.
Niels Bohr was born in Copenhagen on October 7, 1885 as the son of Christian Bohr, a Professor of Physiology at Copenhagen University. Neil along with his younger brother Harald grew up in an atmosphere that helped develop their intellectual beings. Due to the reputation and guidance of his father, Neil Bohr later went on to Copenhagen University where he came under the guidance of Professor C. Christiansen a highly endowed physicist. Bohr graduated with his master’s degree in 1909 and his doctor’s degree in 1911. Neil Bohr began to conduct his experiment in 1913. Through his research he created the Bohr Model which was a model of the atom that consisted of a small positively charged nucleus surrounded by orbiting electrons. Neil Bohr realized that electrons had different energy levels. He determined this by placing different gasses in tubes and heating them up. When heated, the gases lit up in different colors. Bohr was correct in that electrons had different energy levels but there were a few problems. One problem was that it violates the Heisenberg Uncertainty Principle because it considers electrons to have both a known radius and orbit. It also made poor predictions regarding the spectra of larger atoms. Although there were problems with his experiment, Bohr’s conclusion to his experiment was correct.
by Jalen Horton November, 2013
The Electron Cloud Model Scientists Niels Bohr Erwin Schrodinger Werner Heisenberg Info Niels Bohr proposed that electrons circle around the nucleus of an atom on a fixed path in the early 1900’s. In 1926 Erwin Schrodinger thought different; he proposed that electrons are not in a fixed circle, they are floating in different orbitals like clouds around a dense nucleus. Erwin Schrodinger and Weiner Heisenberg use mathematics to probably locate the electrons location around the nucleus. They referred to this as “lobes” the probability to locate electrons. My partner and I think using mathematics finding electrons that can’t usually be seen by a naked eye or a powerful microscope is ridiculous. But the discovery of this model created the electron configuration chart that can be use find the atomic number of an element on the periodic table.
By Kenny Shields & Andrew Swessinger November, 2013
Planetary Model by Kat Finch
November, 2013
The planetary model was proposed by Niels Bohr when he set out to define the laws of the electrons. Rutherford had just a few years before convinced the world of the electrons existence. Now with power, light and a lot of calculations Bohr explained their behavior. Bohr used an outside source of energy and ran it through atoms. The energy absorbed by the atom allowed the electrons to drop a level of orbit. As the electrons dropped the light given off by the element changed. Bohr was able to measure, record, and link this change to the orbits of the electrons. Bohr model was a step in the right direction; however it did not explain the atoms stability. The laws of physics didn’t allow for his model to work and have the atom be stable. Bohr created a work around that would allow his model of fixed orbits to work and have a stable atom. This was not well done and was not proper science. Niels Bohr’s experiments helped get closer to the truth of the atom than ever before. They helped create the rules that govern the electron and progress forward with discover.
By: Keenan Jackson & Kendra McGhee Nov. 5, 2013 Ernest Rutherford, a famous nuclear physicist, discovered that the atom was not the smallest unit of mass. Rutherford discovered a tiny, dense, region of an atom that he called the "nucleus". The nucleus is made of protons and neutrons; it was also surrounded by negative orbiting electrons. Rutherford’s experiment all started out as a test to the plum pudding atomic model. Rutherford’s experiment consisted of alpha particles and thin, gold foil. The alpha particles were shot at the piece of gold foil and either bounced off the material or went through it. Rutherford noticed that the alpha particles that passed through the foil were scattered at large, various angles. This observation led Rutherford to believe that the alpha particles collided with a particle much larger than themselves while passing through the gold foil. He discovered that the alpha particles were hitting an atom called the nucleus, which caused the atoms to scatter at large angles. Rutherford’s discoveries were very important, but now we know that his atomic model is still incorrect. Ernest Rutherford knew that there were negatively charged particles surrounding the nucleus, but he did not know that the electrons were on scattered rings surrounding the nucleus and also that these electrons were constantly moving. A few years later a scientist named Niels Bohr, discovered that electrons are constantly in motion on rings. Although there were flaws in Ernest Rutherford’s theory, he is still one of the greatest physicists of all time. Ernest Rutherford’s discovery had a huge impact on society. Due to the innovation of the nucleus, scientist where able to make other discoveries based off of his findings, causing a ripple effect to the scientific world. Rutherford’s work contributed to the discovery of the atomic number, and without the atomic number The Periodic Table of Elements would not be organized the same.
By Stephanie Murdock
November, 2013
The neutron was very powerful discovery. In 1920 Ernest Rutherford discovered the possibility that neutrons could exist in the atom. The neutron wasn’t fully discovered until 1932 by James Chadwick who used scattering data to calculate the mass of the neutral particle. Rutherford discovered the idea of neutron when he saw that there was neutral mass in the atom. He unfortunately didn’t discover it because he was unable to find the evidence of neutral particles. Scientists in the 1920’s generally accepted an incorrect model of the atom. The model atom only consisted of protons and electrons. In 1930 it was presumed that the atom was composed of only a relatively small nucleus, electrons and protons. It was also thought that there were electrons in the nucleus, after the discovery it was clear that there are no electrons in the nucleus. As soon as this new model was discovered it was accepted by most scientists right away. The model says that the atom consists of a nucleus that is filled with protons and neutrons where the outside of the atom consists of electrons. Rutherford’s idea was revolutionary for the time being. It led to a better understanding of the atom and we still learn about this model today. This idea really impacted the way we look at the atom. It wasn’t until James Chadwick came along and found the evidence Rutherford was missing to fully confirm the existence of neutrons. It is apparent that Rutherford and Chadwick worked together on their atomic model.
By: Tylen Chestnut and Jasmin Jabbar, Faith Gaye November 2013 How do you identify what something is and how it works? Scientist always discovers new things. With their discoveries we learn how things work and how it will benefit the rest of the world. One of the biggest scientific discoveries is the atom, which is found in different types of elements, which are part of the periodic tale. A scientist named Joseph Thomson first discovered the idea of an atom and what it looks like. His work started in the late 1800’s. He had a general model of what the atom looked like. Thomson used more than one similar element also known as isotope. The atom was a large positively charged body containing electrons surrounded by the positive charge. This was model was known as the Plum Pudding Model. He discovered what was in the atom by using the cathode ray .The experiment was correct about atoms; they are primarily composed with space. But there were holes in this logic. If the electrons in an atom keep adding on to each element in turn there would never be a case where the mass of the electrons goes down. The mass always increases. This picture sums up Thomson’s theory, the chocolate chips represents the negative electron; while the whole cookie represent a positive charged body.
Thomson’s Plum Pudding Model has been significant to our society by helping scientist create many more types of models that are based from his theory. Every field of science needs a template to base off of and improve work on Thomson created just that. Thompson plum pudding model was the first to discover what was inside of atoms. In the early 1900s Ernest Rutherford then later expanded off Thomson’s model as later scientist did.
by Renee Elliot & Lejla Subasic
The electron cloud model is a model of the atom, although it may seem different to what most people are acquainted with. In this model electrons are not shown to be orbiting around the nucleus on a strict path. This model depicts that we may never know the specific orbits that electrons take around the nucleus; instead they are described as a cloud of electrons. The first shell holds two electrons while all subsequent shells hold eight electrons. The number of electrons in a given atom is equal to the number of protons in that atom. However, atoms of the same element can have different numbers of electrons. Such atoms are known as ions. The electron configuration of the filling of orbitals, as well as emergence of the s, p, d and f "blocks"
The electron cloud model was born from quantum mechanics. Within the basic concepts of quantum mechanics is the idea that being able to determine something for absolutely certain is wrong. That we can never be completely accurate about the momentum and position of a particle, even if we know the initial position or momentum and forces involved. This completely contradicts Newtonian mechanics. Within the limits of quantum mechanics scientists can only predict a particle’s preceding location or momentum. This helped give birth to the idea of the electron cloud model. When you take an atom with many electrons the regions of orbit spreads out and forms a fuzzy ball, which backs up the idea of quantum mechanics and the uncertainty principal. When the electrons form the cloud shape it is impossible to determine specifically where their orbital paths are. Within, the electromagnetic spectrum, the Electron Cloud is actually a Wave Function, which describes the probability of finding an electron in a particular region of space around a central nucleus. The cloud model represents a record of where the electrons have most likely been before and it will probably be going. The electrons penetrate more towards the nucleus screening from the charge of intervening electrons. Thus, in atoms of higher atomic number, the of electrons becomes more and more of a determining factor in their energy, and the principal quantum numbers of electrons becomes less and less important in their energy placement. Electrons leave a trace of where they’ve been when they move on their orbital paths, and when we look at the traces the electrons leave behind it forms the cloud. Schrodinger’s probability equation predicted the probable locations of the electron, which happen to coincide with the locations that Bohr specified in his model, where they are subject to less.
By: Andrew Morgan and Alex Colby
November, 2013
The planetary model is a long combined effort of multiple scientists but finally developed by Ernest Rutherford in the year 1911. His model has been the second to last model designed for the atom after three other scientists failed to figure it out. This model has recently been considered a false representation of the actual model. The planetary model is called this because the nucleus sits in the middle like the sun and then electrons circle the nucleus like planets would the sun. He figured this out by using the experiment “gold foil experiment” where he has machine shooting alpha particles which is two protons and two neutrons. Alpha particles would fire off and be deflects and shots off into a different direct missing the gold foil set up in the middle. The alpha particles acted like two positive magnets coming together with the gold foil. This disproved the “plum pudding model” showing the particles were not in fact in the nucleus but is deflected by it. Now why was this disproved so many years later? Well new things where found like the nucleus and electron’s and that where the new model came out with the theory that the atom is not only a nucleus with alpha particles surrounding it but also incased in a cloud made of electrons. And how is this different from Rutherford’s Model? Well first of all Rutherford did note that there are electrons but not specific of where they are located. The new electron cloud model uses mathematical problems so shows a close location of where the electrons are located and that they are always moving. Although his model was proven in fact wrong it was still an amazing milestone in the atomic science world. His work helped us find the current model and maybe even one day find out the actual model of the atom. Only to find out that we were completely wrong these are the things that make the atom the world’s greatest mystery and Rutherford is one in a million able to have the ability to try and solve this model. Rutherford will always be remembered as a late great scientist and his work even though wrong will always be remembered in history.
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