Historical Development of Atomic Structure Yazan Fahmawi Sept. 30, 1995 T3 IBS Chemistry Ms. Redman The idea behind the "atom" goes back to the Ancient Greek society, where scientists believed that all matter was made of smaller, more fundamental particles called elements. They called these particles atoms, meaning "not divisible." Then came the chemists and physicists of the 16th and 17th centuries who discovered various formulae of various salts and water, hence discovering the idea of a molecule. Then, in 1766 was born a man named John Dalton born in England. He is known as the father of atomic theory because he is the one who made it quantitative, meaning he discovered many masses of various elements and, in relation, discovered the different proportions which molecules are formed in (i.e.
In the 1700’s, Antoine Lavoiser wrote the first extensive list of elements and categorized them into metals and non-metals . Johann Wolfgang Döbereiner and Alexandre-Emile Béguyer de Chancourtois also tried to classify the elements in the mid 1800’s but were not extremely successful. Döbereiner classified elements into triads with elements with similar properties while Béguyer de Chancourtoiswas the first to notice that when elements are arranged by their atomic weights, groups of elements ... ... middle of paper ... ...he same regardless of the type of atom. He then concluded that atoms consist of tiny, negatively charged particles. He, like Chadwick, received a Nobel prize for his work in 1906 .
His law was the first useful atomic theory of matter. Another theory he had stated that total pressure let out by a mixture of gasses is the total of the pressures of all individual gasses in the mixture: in other words, he concluded evaporated water exists in air as an independent gas. Dalton tried his expiriments many times to make sure that his theory was right. To be exact Dalton tried his expiriments about 200,000 times! Dalton also developed a hypothesis that the sizes of the particles making up different gases must be different.
Atomic Theory In the beginning of the 1800s John Dalton, an English scientist did work some work on gases, which lead him to the creation of a complex system of symbols for all known elements at the time. He took all the information he had collected, along with the Laws of Conservation of Mass, Definite Composition and Multiple Proportions and updated Aristotle's theory of matter with the Atomic Theory of Matter, which stated: - All matter is composed of tiny, indivisible particles called atoms. - Atoms of an element have identical properties. - Atoms of different elements have different properties. - Atoms of two or more elements can combine in constant ratios to form new substances.
Chemistry has been around since the earth was created, a time when computers, televisions, or simple beakers weren’t invented yet. Chemistry was always around, but it wasn’t considered a science until modern chemistry was discovered. Modern chemistry has only been around for centuries, where author Robert Boyle published The Skeptical Chemist in 1661. Soon after Robert’s publication, Antoine Lavoisier developed the law of conservation of mass, and that was the start of modern chemistry being considered a science. After this, chemistry was changed forever.
Exploring the Role of Chemists It was Lavoisier who divided the few elements known in the 1700's into four classes, and then John Dalton made atoms even more convincing, suggesting that the mass of an atom was it's most important property. In the nineteenth century Johann Döbereiner was the first to attempt to classify elements using their relative atomic mass. He also identified a number of ‘triads’ in the list of elements then known. Each triad was a set of 3 elements that have similar properties (e.g. Cl, Br and I; Ca Sr and Ba).
Some of the very first recorded chemist where men like democritus and aristole. These men where alive in the B.C era and have a lot of influence on how we do modern chemistry today. Starting with Democritus the man who claimed that the atom is the simplest unit of matter. Democritus of ancient greece asked the question could matter be divided into smaller and smaller pieces forever or was there a limit to the number of times a piece of matter could be divided? Democritus had a theory that it would eventually get to small to cut anymore.
Only six short years later, in 1845, Sir William Grove utilized Schoenbein’s discovery to create the very first functioning hydrogen gas battery. It is for this reason that Grove is known as the ‘Father of the Fuel Cell.’ Both a physicist and inventor, Sir William Grove, developed the concept of generating electrical power by means of introducing oxygen and hydrogen in the presence of an electrolyte almost 170 years ago. He conceived the first hydrogen fuel cell in 1839 and developed a working prototype. Although he is credited with this invention, the reality is that his concept and experimentation were far more valuable than the actual cell itself as it was unable to ... ... middle of paper ... ... accounts for 95% of the hydrogen produced today. In addition to steam reforming, another natural gas-hydrogen process called partial oxidation produces hydrogen by burning methane in the presence of air.
Although it was Lavoisier who had divided the very few elements known in the 1700's into four different classes, and then John Dalton made atoms even more believable, telling everyone that the mass of an atom was it's most important property. Then in the early 1800's Dobereiner noted that the similar elements often had relative atomic masses, and DeChancourtois made a cylindrical table of elements to display the periodic reoccurrence of properties. Cannizaro then determined atomic weights for the 60 or so elements known in the 1860s, and then a table was arranged by Newlands, with the many elements given a serial number in order of their atomic weights, of course beginning with Hydrogen. That made it clear that "the eighth element, starting from a given one, is a kind of a repeat of the first", which Newlands called the Law of Octaves. Then both Meyer and Mendeleyev built periodic tables alone, Meyer more impressed by the periodicity of physical properties, while Mendeleyev was more interested in the chemical properties.
His first paper explained the photoelectric effect, the second offered experimental proof of the existence of atoms, and the third introduced what we know today as the theory of special relativity. The last paper to be published introduced his formula “m=E/c2” which would later be tweaked to the recognized form we know today, “E=mc2”. 1905 remains to this day one of the most significant years in history for the field o... ... middle of paper ... ...ngle is a sum of 180 degrees. Utilizing the same concept when creating a symbol to simplify inductive reasoning we can declare deductive reasoning as a “top-down” concept and this could be used as an aid to declare a statement as using deductive reasoning. I chose inductive/deductive reasoning as my basis to creating a symbol because in the beginning of the semester I too had trouble understanding this basic concept.