The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. Atoms lack a well-defined outer boundary‚ so their dimensions are usually described in terms of an atomic radius. This is a measure of the distance out to which the electron cloud extends from the nucleus. However‚ this assumes the atom to exhibit a spherical shape‚ which is only obeyed for atoms in vacuum or free space. Atomic radii may be derived from the distances
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Atoms‚ Molecules and Elements Atoms‚ molecules and elements are the building blocks of everything we can see‚ hear‚ and touch. Though not visible to the naked eye‚ it is the combination of millions of these tiny substances that make us who and what we are today. Many elements make up the world around us‚ and each element reacts differently to its surroundings. The definition of reactivity as pertained to chemistry states‚ “The relative capacity of an atom‚ molecule‚ or radical to undergo a chemical
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Atoms‚ Molecules‚ and Elements CHM/110 William De Vorick June 30‚ 2014 Atoms‚ Molecules‚ and Elements Demetri Mendeleev was trying to organize the elements into a table by weight when he noticed that as the weights increase occasionally the properties of one element would resemble those of an element he already listed so he placed these elements in a column under the ones they resembled chemically ( Capri‚ PhD‚ 2003). Each chemical in the vertical rows on the periodic table are considered
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Atoms Atom is the fundamental building block of all stuff‚ or what scientists like to call "matter". An individual atom is very small. In fact‚ the smallest type of atom‚ hydrogen‚ has a diameter of 10-8 cm. Every single object is composed of atoms. Our body is made up of many‚ many individual atoms. There are also many different types of atom. These different types are called elements. Examples of some elements are hydrogen‚ oxygen‚ and helium. Under normal conditions many atoms can stick together
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1: The atom Introduction Atoms are the building blocks for matter Everything is made up of atoms 1A: Sub-atomic particles Atoms are made up of 3 sub-atomic particles‚ 2 of which are located in the nucleus (the heart of the atom) Positively charges protons and neutrally charged (non-charged) neutrons are found in the nucleus Negatively charged electrons are located orbiting the nucleus in shells. They stay in orbit because the electrons are attracted to the protons 2: The Element
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Chapter 5: Electrons In Atoms A. Models of the atom i. The Development of Atomic Models Protons and neutrons make up a nucleus surrounded by electrons Rutherford’s model or theory ( figured electrons move around the nucleus) His theory didn’t explain why metals or compounds of medals give off characteristics of colors when heated. Also didn’t explain why the atomic model could not explain the chemical properties of elements ii. The Bhor Model Bohr proposed that an electron is found in specific
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Atoms make up everything around us‚ including ourselves. They consist of protons which give off a positive charge‚ electrons which give off a negative charge and neutrons which have no charge. In an atom there are the same amount of protons as there are electrons. If there weren’t it would cause the atom to behave differently. Atoms have layers around them called shells which contain electrons. Each shell can only hold a certain amount of electrons. Molecules can be multiple atoms of the same element
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Subatomic particles Main article: Subatomic particle Though the word atom originally denoted a particle that cannot be cut into smaller particles‚ in modern scientific usage the atom is composed of various subatomic particles. The constituent particles of an atom are the electron‚ the proton and the neutron. However‚ the hydrogen-1 atom has no neutrons and a positive hydrogen ion has no electrons. The electron is by far the least massive of these particles at 9.11×10−31 kg‚ with a negative
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NOT base your answer on tabulated values since exceptions may occur. | germanium smallest arsenic selenium bromine largest Feedback: Electronegativity is the ability of an atom in a molecule to attract electrons to itself. In general‚ electronegativity increases as the atomic radius decreases. Smaller atoms have higher electronegativities. Notice that all of these elements are in row 4. Across a row of the periodic table‚ atomic radius decreases with increasing atomic number. The
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Atoms are the smallest entities which resemble the properties of an element and cannot be broken down into smaller parts. Molecules are formed when two or more atoms are combined. This formation can happen in a variety of ways. When two oxygen atoms join O2 is formed‚ and when three oxygen atoms join O3 or ozone is formed. Both of these have different properties. Different atoms can also combine to form molecules. Hydrogen combines with sulfur to form H2S and hydrogen and oxygen also combine
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