... and chemistry. One mistake of Dalton was his belief that atoms were round and hard. This became the primary ambition for scientists after Dalton, to find out the structure of an atom. In 1897, Joseph John Thomson discovered electrons. Using a tube, magnets and charged plates, he sent ray particles through various experiments changing the position of the charged plates. By changing the plates, he discovered he could also change the point at which the particles would hit a florescent screen at the end of the tube. He decided that the ray was made up of particles with a negative charge. He named these particles electrons. This discovery also showed that ato ...
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... girls could not attend universities in Poland. Marie’s older sister, Bronya, had already left Poland to study medicine at a university in Paris. Marie sent a portion of her earnings as tutor and governess to Paris to help pay for her older sister’s medical studies. In 1891, when Marie was twenty- four years old, she was invited to live with Bronya upon her completion of medical school. This enabled Marie to enroll at the University of Paris and begin her own dream of becoming a university student. Marie studied mathematics, physics, and chemistry. It was upon enrollment in college when she changed her first name from Manya to Marie. After three years of her ed ...
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... did the inventors conclude that more propulsive power could be obtained by merely straightening out the surface of the airscrew blades. Attempts to utilize the "straight blade" propeller were made by balloonists. These contraptions were quite strange and hardly fulfilled their purpose of actually propelling the balloon. The basic propeller had evolved from the simple concepts of da Vinci, and was slowly becoming an effective means of aerial propulsion. To reach the next plateau of flight an increased knowledge of the propeller would be needed, and the mysteries of the propeller and mechanical power would need to be solved. These substantial tasks rema ...
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... natural systems are becoming significantly concerning. The worldˇ¦s population, currently 5.2 billion has grown from about 3 billion in 1960, and around 2 billion in 1925. Today it increased by almost 90 million each year, and is likely to reach 10 billion by 2025(Corson 4). The reason we currently have an atmosphere crisis is because of human impact on the gases which make up our atmosphere. Our atmosphere, which is made up of four distinct layers blankets our planet and protects up in many way. One way it protects us if from the harmful rays the sun radiates on our planet. Each layer differs from the others in temperature, density, composition and in the way ...
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... Constructive interference occurs when two waves of the same frequency meet at a crest or trough therefore combining to form a wave that has an amplitude equal to the sum of the individual amplitudes of the original waves. Stimulated emission is the process that the laser works on, which was first proposed by Albert Einstein in 1917. When a sufficient number of atoms, either gas solid or liquid, absorb energy so that they are in an excited state of higher energy stimulated emission can occur. Light of a specific wavelength can produce more light with the same phase and direction these light waves will be coherent. Stimulated emission amplifies the cohere ...
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... traits in children, a practice which has come to be called “negative .”2 In the late nineteenth century, a man named Francis Galton gave eugenic thought great emphasis.3 Yet it was not until Gregor Mendel’s theories on genetics were rediscovered by Charles Davenport in 1901 that the ideas of modern was given any credibility.4 Davenport conducted experiments that proved what Mendel had said years before in his laws of genetics. Davenport, however, took it another step. He extended Mendel’s laws to include characteristics such as pauperism, alcoholism, and the popular term of the day, “feeblemindedness.”5 Davenport also connected behavior to race, class, a ...
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... of how to conduct themselves in society. They have not had time to learn the social standards of their time. So with this limited knowledge, children will consistently react to situations in a similar way that can only be explained by an instinctive nature. Have young children changed their behavior since the 1700's? I suppose any child from any culture at any time in history would cry when it was upset, physically take whatever it wanted, need a certain amount of love and attention, and also be interested in exploring things outside of it's bounds. I feel that all of these instinctive behaviors seen in young children are emotions that I, as a young adult ...
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... health effects including cancer, birth defects, reproductive harm, neurological and development toxicity, immunotoxicity, and disruption of the endocrine system.” Children are more likely to be affected by pesticides than adults because, they are strange eaters, they breath at a higher rate, and tend to spend more time on the ground were chemicals may settle and then enter a child’s body through breathing, orally, by touching something with a residue and then putting their fingers in their mouth, and through a child’s skin. Pesticides will drastically damage the future health of our children if people don’t act now. CHILDREN’S HEALTH IS AT RISK THROUGH THE FOO ...
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... and its origin. The above example shows only a few examples of autistic behavior. The history of autism extends, as far back as the late sixteenth century; however, during that time it was not identified as this illness. Here is a statement from before the discovery of the illness: In 1799, a boy about eleven years of age was found naked in the woods of Averyron, France. He was dirty, covered with sores, mute, and behaved like A wild animal. Jean Itard, the physician of the new institution for deaf-mutes, Was given charge of the abandoned child. From Itard’s description, Victor Showed many features of autism—he did not look at people and never Played with t ...
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... feet) At this point s would be broken down by short-wavelength ultraviolet radiation from the sun. This radiation is the one which would not reach the lower atmosphere in large amounts because of the ozone layer. When these s do brake down, they released atomic chlorine which then would react with the ozone and convert it back into plain oxygen. The even worse part of all this is that these chlorine molecules do not become inactive after the first reaction with the ozone and would be available to destroy more ozone molecules. Thus this process would be the function of a catalyst; a single chlorine atom involved in a chain reaction to destroy many ozone molecules. ...
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