Chemistry is the science of composition, structure, and the specific properties of matter. It also examines who matter interacts and changes through various processes. This science is pivotal to astronomy, medicine, engineering, and food processing. The electronics industry could not exist without it. Like other sciences it has major branches, that examine particular questions. Chemistry can be seen everywhere in the natural world. It tells humankind the composition of the stars to the internal interactions of human cells. Chemistry developed from alchemy. It was a partially scientific and philosophic discipline, which developed in certain ancient civilizations. The rise of modern science discredited alchemist convictions. Now there are various fields of chemistry which include: analytical chemistry, biochemistry, electrochemistry, environmental chemistry, geochemistry, inorganic chemistry, nuclear chemistry, organic chemistry, photochemistry, physical chemistry, radiochemistry, and stoichemistry. Like other sciences it went through various phases of development and change.
Chemistry developed from the practice of alchemy. It is unclear who developed it first, but Chinese, Egyptian, and Greek civilization made contributions to alchemy. The practice of alchemy was not purely out of curiosity. The goal was to transmute substances to different ones. Taoists and the Pythagoreans were attempting to turn certain metals into gold. The desire to produce gold in such a manner would have been lucrative. There was also another goal the early alchemists sought: the mythical philosopher's stone. It was believed through alchemy illness could be cured and the philosopher's stone could be created. The stone that alchemist sought was thought even to make a person immortal. There was no scientific basis for this, but alchemy remained dominant until the Middle Ages. Although the classical world was limited in precise scientific knowledge, there were thinkers who were already examining matter. Democritus a Greek philosopher was convinced the foundation of matter was particles know as atoms. Greek civilization examining the works of Chinese and Egyptian alchemy, extrapolated that matter was composed of four elements. Fire, earth, air, and water was the base of all matter. Paracelsus by the 1500s took alchemy in a different direction. The Swiss doctor proposed that there were many different types of metal and therefore more than four elements. He believed that alchemy should not be used to produce gold or create a philosopher's stone , but to have a better understanding of science. Alchemists reacted negatively to his assertions and repudiated him. Others however, embraced his theories. Libavius one of his followers, produced an early chemistry text. As alchemy declined it would result in the birth of chemistry.Observations and data gathered by alchemist gave early chemists a based to work from.
The major turning point for this filed of science came in 1660. King Charles II of England found the Royal Society of London and the members would later go on to produce new knowledge. One natural philosopher who made a significant impact was Robert Boyle. He was in many ways was one of the first modern chemists. Boyle was one of the first chemists to do controlled experiments rather than just observation. Through this method of controlled experimentation, he made a discovery about gases. When the volume of a gas is decreased, pressure will rise proportionally. This phenomenon is known as Boyle's law. Boyle also introduced a litmus test to distinguish acids from bases. Besides introducing chemical tests, he developed the modern concept of the nature of elements .
From the 1600s onward chemistry would continue to advance. During the 18th and 19th centuries various chemist would uncover the nature of matter and chemical reactions. Karl Scheele, Joseph Priestley, and Antoine Lavoisier identified new elements and were explaining chemical reactions such as combustion. John Dalton came to the conclusion that compounds had to be formed by atoms of elements. He also proposed that atoms of the same element combine to form molecules.Dalton also stated they combine into a simple ratios. Dalton's new atomic theory and the identification of numerous elements required a system of classification.
When more elements became known they had to be organized in a system to best understand them. The Periodic Table of Elements was formed to classify the growing discovery of different types of matter. The Periodic Table of Elements lists the elements by their chemical symbol and physical characteristics. The number of elements listed are between 109 to 112 known elements. The transuranium elements are synthetic productions of human chemical engineering. Humanity was not always ignorant of chemical elements. At the time of the early common era, About nine elements were known. These elements were lead, gold, copper, sulfur, mercury, tin, silver, carbon, and iron. At that time the number of known elements was low and the need for classification was not necessary. When time passed more elements would be discovered. Johann Dobereiner and John Newlands observed that atomic masses had a relation to an elements chemical properties. These two chemists one German the other English had stumbled unto something pivotal. It was a starting point to a standardized system of classification of elements. Lothar Meyer expanded upon their findings. His method was to have repeating patterns in properties be organized in relation to their atomic mass.
Chemistry developed from the practice of alchemy. It is unclear who developed it first, but Chinese, Egyptian, and Greek civilization made contributions to alchemy. The practice of alchemy was not purely out of curiosity. The goal was to transmute substances to different ones. Taoists and the Pythagoreans were attempting to turn certain metals into gold. The desire to produce gold in such a manner would have been lucrative. There was also another goal the early alchemists sought: the mythical philosopher's stone. It was believed through alchemy illness could be cured and the philosopher's stone could be created. The stone that alchemist sought was thought even to make a person immortal. There was no scientific basis for this, but alchemy remained dominant until the Middle Ages. Although the classical world was limited in precise scientific knowledge, there were thinkers who were already examining matter. Democritus a Greek philosopher was convinced the foundation of matter was particles know as atoms. Greek civilization examining the works of Chinese and Egyptian alchemy, extrapolated that matter was composed of four elements. Fire, earth, air, and water was the base of all matter. Paracelsus by the 1500s took alchemy in a different direction. The Swiss doctor proposed that there were many different types of metal and therefore more than four elements. He believed that alchemy should not be used to produce gold or create a philosopher's stone , but to have a better understanding of science. Alchemists reacted negatively to his assertions and repudiated him. Others however, embraced his theories. Libavius one of his followers, produced an early chemistry text. As alchemy declined it would result in the birth of chemistry.Observations and data gathered by alchemist gave early chemists a based to work from.
The major turning point for this filed of science came in 1660. King Charles II of England found the Royal Society of London and the members would later go on to produce new knowledge. One natural philosopher who made a significant impact was Robert Boyle. He was in many ways was one of the first modern chemists. Boyle was one of the first chemists to do controlled experiments rather than just observation. Through this method of controlled experimentation, he made a discovery about gases. When the volume of a gas is decreased, pressure will rise proportionally. This phenomenon is known as Boyle's law. Boyle also introduced a litmus test to distinguish acids from bases. Besides introducing chemical tests, he developed the modern concept of the nature of elements .
When more elements became known they had to be organized in a system to best understand them. The Periodic Table of Elements was formed to classify the growing discovery of different types of matter. The Periodic Table of Elements lists the elements by their chemical symbol and physical characteristics. The number of elements listed are between 109 to 112 known elements. The transuranium elements are synthetic productions of human chemical engineering. Humanity was not always ignorant of chemical elements. At the time of the early common era, About nine elements were known. These elements were lead, gold, copper, sulfur, mercury, tin, silver, carbon, and iron. At that time the number of known elements was low and the need for classification was not necessary. When time passed more elements would be discovered. Johann Dobereiner and John Newlands observed that atomic masses had a relation to an elements chemical properties. These two chemists one German the other English had stumbled unto something pivotal. It was a starting point to a standardized system of classification of elements. Lothar Meyer expanded upon their findings. His method was to have repeating patterns in properties be organized in relation to their atomic mass.
Still a standardized table had not been created. It was not until 1869 that Dmitri Mendeleev did the first Periodic Table of Elements form. For the first time the elements were put into an organized table. The Russian chemist determined that the elements characteristics are a function of both atomic mass and period function. Mendeleev had discovered the periodic law of elements. Elements were to placed in families or groups on this table. Mendeleev left blank spaces for elements assuming more would be found in the future. He was correct in that conjecture and ever since the Periodic Table of Elements has been expanding.Mendeleev noted the cycle of repetition of chemical properties revolves around eight elements. However, this does not continue for elements that are much heavier. The heavier elements function on a cycle of 18. The Periodic Table of Elements would require adjustments.
Henry Moseley refined periodic law. Moseley proclaimed that physical and chemical properties are rooted in the the periodic function of atomic number. He gave a better explanation for why their are gaps in the periodic table. The electron was eventually discovered to be the key to knowing the properties of elements. The earlier chemists were getting close to to this conclusion. Some chemists, even Dmitri Mendeleev refused to accept the electron even existed. The Periodic Table of Elements continues to be a useful tool to both chemists and physicists.
Chemistry is not just one monolithic subject area, but has multiple branches. These branches can be in both areas of applied science or pure research. It has made an immense impact on industry and human civilization. There is a difference in subdivisions and branches, which seek to answer particular questions. Analytical chemistry examines substances and the attributes of their various components. The goal is to understand the structure from every angle. Astrochemistry studies material from space. The discovery of new exoplanets makes this branch particularly exciting. The astrochemist examines asteroids, rocks, and other matter from space. The possibilities are endless considering it has been suggested that the universe is expanding. Biochemistry wants to comprehend the chemical interactions and functions of life forms. Electrochemistry directs its focus toward the flow of electricity and the relationship between chemical changes. Environmental chemistry seeks to examine the natural environment of Earth through chemical processes and its impact on life forms. An extension of this is geochemistry explaining the chemical structure and composition of rocks and minerals Nuclear chemistry explores the changes in the nucleus of the atom. Organic chemistry delves into hydrocarbons and compounds of living organisms ( inorganic studies the opposite which includes compounds that do not have carbon). Photochemistry wants to discover the effects of light and ultraviolet radiation on particular elements. Stoichemistry looks at the science in terms of mathematical relationships. Chemical reactions are expressed and described in formulas.
Physical chemistry combines the elements of physics with chemistry. This is a practical union, because the universe is governed by fundamental forces. Radiochemistry studies the strange behavior of radio isotopes. Chemistry is both an applied science and part research. These specialized field have not only added to human material gain, but a new body of knowledge.
A major part of chemistry is understanding matter. It can be classified in numerous ways. Matter can have three states which include solids, liquids, and gases. There is also a fourth state known as plasma. Matter can only reach this state at immense temperatures. The basis of matter at its most diminutive unit is the atom. Atoms can combine together to form molecules. Physicists have confirmed the existence of the higgs boson, which may explain why objects have mass. This will certainly bring colossal changes to chemistry.Matter had three main classifications which include further categories. Elements can include metals and nonmetals. Elements can not be deconstructed into other substances. Compounds can be divided into either covalent or ionic bonds . They are two or more elements combined in terms of a definite proportion, which explains the rise of more complex matter. Both elements and compounds are homogeneous. Mixtures can either be homogeneous or heterogeneous. Mixtures combine two or more substances, but still maintain their unique properties. A solution is a mixture and it still contains uniformity. Colloidal dispersions are also mixtures in which particles are loose in a solvant. Interactions between particles is key to comprehending physical and chemical properties.
Chemical reactions are the result of bonds between atoms. The constructed and reorganized bonds make new products from the original reactants. Chemical reactions can happen in nature or be induced by other means. The time it takes for a chemical reaction to occur can vary. Some may take a number of years or spark instantaneously. Energy can change during a course of these reactions.A burning reaction leads to new bonds between atoms, which result in the release of heat and light. The heat that is projected can also be referred to as an exothermic reaction. Most chemical reactions are not reversible. There are some chemical reactions that have the ability to take place in either direction ;this means a few can be reversible. Decomposition reactions involve two compounds breaking down and reforming in a solution to produce two new substances. The action could result in forming a precipitate, displacement, or another element displaces separate from the solution. The reaction rate can be determined by size, shape, and temperature of the reactants. When describing this process chemical symbols are used.
Understanding chemical reactions has given humanity the ability to advance pharmaceuticals, medicine, and the electronics industry. The semiconductor industry would not exist without chemistry. Silicon can be found in most computer chip technology, because it can be treated chemically to be a useful conductor. Silicon is not as conductive in its unaltered state. This can also be done with germanium, which is also present in computer technology. It can not be ignored when chemical reactions occur it involves energy. It explains the ability to do work and comes in various forms. Energy can come in the form of light, heat, sound, electrical, chemical, and nuclear reactions. The Law of Conservation states that energy is fixed through out the universe. Energy can be both potential and kinetic. Energy flows through the universe neither being created or destroyed. The workings of compounds, mixtures, elements, and solutions demonstrate this. Science is interdisciplinary and chemistry is no exception. Understanding energy requires knowledge of both physics, chemistry, and biology. Like other sciences chemistry will continue to unmask the mysteries of existence.
References
Hall, Nina. The New Chemistry. Cambridge: Cambridge University Press, 2000.
Barnes-Svarney, Patricia L. The New York Public Library Science Desk Reference. New York: Macmillan USA, 1995
DK Ultimate Visual Dictionary 2000. New York: DK Pub., 1999.
No comments:
Post a Comment