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ATOMS

 

What is your body made of? Your first thought might be that it is made up of different organs—such as your heart, lungs, and stomach—that work together to keep your body going. Or you might zoom in a level and say that your body is made up of many different types of cells. However, at the most basic level, your body—and, in fact, all of life, as well as the nonliving world—is made up of atoms, often organized into larger structures called molecules.

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Atoms and molecules follow the rules of chemistry and physics, even when they're part of a complex, living, breathing being. If you learned in chemistry that some atoms tend to gain or lose electrons or form bonds with each other, those facts remain true even when the atoms or molecules are part of a living thing. In fact, simple interactions between atoms—played out many times and in many different combinations, in a single cell or a larger organism—are what make life possible. One could argue that everything you are, including your consciousness, is the byproduct of chemical and electrical interactions between a very, very large number of nonliving atoms!

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So as an incredibly complex being made up of roughly 7,000,000,000,000,000,000,000,000,000 atoms, you'll probably want to know some basic chemistry as you begin to explore the world of biology, and the world in general.

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Matter and elements

 

The term matter refers to anything that occupies space and has mass—in other words, the “stuff” that the universe is made of. All matter is made up of substances called elements, which have specific chemical and physical properties and cannot be broken down into other substances through ordinary chemical reactions. Gold, for instance, is an element, and so is carbon. There are 118 elements, but only 92 occur naturally. The remaining elements have only been made in laboratories and are unstable.

Each element is designated by its chemical symbol, which is a single capital letter or, when the first letter is already “taken” by another element, a combination of two letters. Some elements follow the English term for the element, such as C for carbon and Ca for calcium. Other elements’ chemical symbols come from their Latin names; for example, the symbol for sodium is Na, which is a short form of natrium, the Latin word for sodium.

The four elements common to all living organisms are oxygen (O), carbon (C), hydrogen (H), and nitrogen (N), which together make up about 96% of the human body. In the nonliving world, elements are found in different proportions, and some elements common to living organisms are relatively rare on the earth as a whole. All elements and the chemical reactions between them obey the same chemical and physical laws, regardless of whether they are a part of the living or nonliving world.

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The structure of the atom

 

An atom is the smallest unit of matter that retains all of the chemical properties of an element. For example, a gold coin is simply a very large number of gold atoms molded into the shape of a coin, with small amounts of other, contaminating elements. Gold atoms cannot be broken down into anything smaller while still retaining the properties of gold. A gold atom gets its properties from the tiny subatomic particles it's made up of.

An atom consists of two regions. The first is the tiny atomic nucleus, which is in the center of the atom and contains positively charged particles called protons and neutral, uncharged, particles called neutrons. The second, much larger, region of the atom is a “cloud” of electrons, negatively charged particles that orbit around the nucleus. The attraction between the positively charged protons and negatively charged electrons holds the atom together. Most atoms contain all three of these types of subatomic particles—protons, electrons, and neutrons. Hydrogen (H) is an exception because it typically has one proton and one electron, but no neutrons. The number of protons in the nucleus determines which element an atom is, while the number of electrons surrounding the nucleus determines which kind of reactions the atom will undergo. The three types of subatomic particles are illustrated below for an atom of helium—which, by definition, contains two protons.

Structure of an atom. The protons (positive charge) and neutrons (neutral charge) are found together in the tiny nucleus at the center of the atom. The electrons (negative charge) occupy a large, spherical cloud surrounding the nucleus. The atom shown in this particular image is helium, with two protons, two neutrons, and two electrons.

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Protons and neutrons do not have the same charge, but they do have approximately the same mass, about 1.67 × 10^{-24}1.67×10−24 grams. Since grams are not a very convenient unit for measuring masses that tiny, scientists chose to define an alternative measure, the dalton or atomic mass unit (amu). A single neutron or proton has a weight very close to 1 amu. Electrons are much smaller in mass than protons, only about 1/1800 of an atomic mass unit, so they do not contribute much to an element’s overall atomic mass. On the other hand, electrons do greatly affect an atom’s charge, as each electron has a negative charge equal to the positive charge of a proton. In uncharged, neutral atoms, the number of electrons orbiting the nucleus is equal to the number of protons inside the nucleus. The positive and negative charges cancel out, leading to an atom with no net charge.

Protons, neutrons, and electrons are very small, and most of the volume of an atom—greater than 99 percent—is actually empty space. With all this empty space, you might ask why so-called solid objects don’t just pass through one another. The answer is that the negatively charged electron clouds of the atoms will repel each other if they get too close together, resulting in our perception of solidity.

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 - https://www.khanacademy.org/science/biology/chemistry--of-life/elements-and-atoms/a/matter-elements-atoms-article

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History of the atom

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The theory of the atom dates at least as far back as 440 B.C. to Democritus, a Greek scientist and philosopher. Democritus most likely built his theory of atoms upon the work of past philosophers, according to Andrew G. Van Melsen, author of "From Atomos to Atom: The History of the Concept Atom." For example, Parmenides, Democritus' teacher, is known for proposing the principle of identity. This principle, which states that "all that is, together forms the being," led to other philosophers, including Democritus, to further his work, eventually leading to atomic theory.

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Democritus' explanation of the atom begins with a stone. A stone cut in half gives two halves of the same stone. If the stone were to be continuously cut, at some point there would exist a piece of the stone small enough that it could no longer be cut. The term "atom" comes from the Greek word for indivisible, which Democritus concluded must be the point at which a being (any form of matter) cannot be divided any more. His explanation included the ideas that atoms exist separately from each other, that there are an infinite amount of atoms, that atoms are able to move, that they can combine together to create matter but do not merge to become a new atom, and that they cannot be divided. However, because most philosophers at the time — especially the very influential Aristotle — believed that all matter was created from earth, air, fire, and water, Democritus' atomic theory was put aside.

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John Dalton, an British chemist, built upon Democritus' ideas in 1803 when he put forth his own atomic theory, according to the chemistry department at Purdue University. Dalton's theory included several ideas from Democritus, such as atoms are indivisible and indestructible and that different atoms form together to create all matter. Dalton's additions to the theory included the ideas that all atoms of a certain element were identical, that atoms of one element will have different weights and properties than atoms of another element, that atoms cannot be created or destroyed, and that matter is formed by atoms combining in simple whole numbers.

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Thomson, the British physicist who discovered the electron in 1897, proved that atoms actually can be divided, according to the Chemical Heritage Foundation. He was able to determine the existence of the negatively charged particles by studying properties of electric discharge in cathode-ray tubes. According to Thomson’s 1897 paper, the rays were deflected within the tube, which proved that there is something that was negatively charged within the vacuum tube. In 1899, Thomson published a description of his version of the atom, commonly known as the "plum pudding model," according to a 2013 article by Giora Hon and Bernard R. Goldstein published in the journal Annalen der Physik. Thomson's model of the atom included a large number of electrons suspended in something that produced a positive charge giving the atom an overall neutral charge, which resembled a popular British dessert that had raisins suspended in a round cake-like ball.

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The next scientist to further modify and progress the atomic model was Rutherford, who studied under Thomson, according to the chemistry department at Purdue University. In 1911, Rutherford published his version of the atom, which included a positively charged nucleus that is orbited by electrons. This model arose when Rutherford and his assistants fired alpha particles at very thin sheets of gold. (An alpha particle is made up of two protons and two neutrons, all held together by the same strong nuclear force that binds the nucleus of any atom, according to the Jefferson Lab.) 

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The scientists noticed that a small percentage of the alpha particles were scattered at very large angles to the original direction of motion while the majority passed right through hardly disturbed. Rutherford was able to approximate the size of the nucleus of the gold atom, finding it to be at least 10,000 times smaller than the size of the entire atom with much of the atom being empty space. Rutherford's model of the atom is still the basic model that is used today, despite its limitations.

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Several other scientists furthered the atomic model, including Niels Bohr (built upon Rutherford's model to include properties of electrons based on the hydrogen spectrum), Erwin Schrödinger (developed the quantum model of the atom), Werner Heisenberg (stated that one cannot know both the position and velocity of an electron simultaneously), and Murray Gell-Mann and George Zweig (independently developed the theory that protons and neutrons were composed of quarks). 

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- https://www.livescience.com/37206-atom-definition.html

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It is from this information that we have reached our first extrapolation.

AXIOM#1:  our reality and this universe it is made of atoms, which are not as solid as they may seem, but rather a myriad of rapidly vibrating energy.

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