he atom is the basic unit of chemical matter. The atom is the smallest unit that defines the chemical elements and their isotopes. Everything that is solid‚ liquid‚ or gas is made up of atoms. Everything that can be seen and touched is made up of atoms. Atoms are tiny; their size is typically measured in picometers (trillionths of a meter). A single strand of human hair is about one million carbon atoms wide.[1] Every atom is composed of a nucleus made of protons and neutrons (hydrogen-1 has no
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Etymology The name atom comes from the Greek ἄτομος (atomos‚ "indivisible") from ἀ- (a-‚ "not") and τέμνω (temnō‚ "I cut")‚[3] which means uncuttable‚ or indivisible‚ something that cannot be divided further.[4] The concept of an atom as an indivisible component of matter was first proposed by early Indian and Greek philosophers. In the 18th and 19th centuries‚ chemists provided a physical basis for this idea by showing that certain substances could not be further broken down by chemical methods
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2) B) 4 liters C) 6 x 1023 atoms D) 2 moles Which sample of O2 contains a total of 3.01 x 1023 molecules at STP? A) 16.0 grams B) 32.0 grams B) 6.02 x 1023 C) 2.00 moles D) 1.00 mole D) 1.20 x 1024 What is the total number of atoms contained in 2.00 moles of nickel? A) 118 C) 58.9 C) 1 liter of neon D) 1 gram of neon 3) 4) What quantity is represented by the symbol Ne? A) 1 mole of neon B) 1 atomic mass unit of neon 5) How many moles of hydrogen atoms are present in one mole of
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Green Chemistry Institute Atom Economy Page 1 American Chemical Society --------------------------------------------------------------------------------------------------------------------- CLEANING UP WITH ATOM ECONOMY By Kathryn E. Parent‚ k_parent@acs.org Introduction Cleaning up the environment and‚ more importantly‚ preventing pollution are important issues in today’s world. The theme for the 2002 National Chemistry Week is “Chemistry Keeps Us Clean.” While the chemical industry is traditionally
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The History of the Atom The History of the Atom Democritus first proposed an atomic model. He said that all matter could be divided into smaller and smaller pieces until a single indivisible particle was reached. He called this particle an atom after the Greek word ‘atomos’ meaning not cuttable. He believed that different atoms are of different sizes‚ have regular geometric shapes and are always in motion. He also said that there is empty space between atoms. Aristotle severely criticized Democritus’
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What are the parts of an atom? Where are the subatomic particles found? The atoms are the smallest units of matter with their own chemical characteristics. The atoms are divided into 2 parts. The first part is the central nucleus and the electron cloud. The central nucleus contains very heavy particles and the electron cloud contains very light moving particles. The subatomic particles are the protons‚ neutrons‚ and the electrons. They are located within the atom and the electrons spin rapidly
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In the past benzene was obtained from the distillation of coal in the absence of air. Today most benzene is made syntheticallyfrom petroleum products. The benzene is a closed ring of six atoms connected by bonds that resonatebetween single and double bonds; each carbon is also bound to a single atom. Benzene isinsoluble in water but mixes in all proportions with organic . Benzene is itself an excellentsolvent for certain and for most simple organic chemicals. It is one of the most commonly
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****Atoms Think and Compare: Page 331 Q-3 Consider these atoms: hydrogen H‚ aluminum Al‚ argon‚ Ar. Rank them‚ from smallest to largest‚ in order of (a) size; (b) number of protons in the nucleus; (c) number of electrons. In order of size from smallest to largest: Hydrogen H‚ Argon Ar‚ Aluminum Al. In order of proton from smallest to largest: Hydrogen H‚ Aluminum Al‚ Argon Ar. In order of electron from smallest to largest: Hydrogen H‚ Aluminum Al‚ Argon Ar. Q-4 Consider these atoms: helium
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The Atom The basic idea of the atom was adopted by scientists thousands of years later because it explained new discoveries in the field of chemistry. Long after chemical atoms were found to be divisible‚ and even after smaller‚ truly indivisible particles were identified. Over time theories of the atom changed. The nature of atoms in philosophy varied a lot over time and between cultures and schools. The Plum Pudding Model was proposed in 1904 before the discovery of the atomic nucleus in order
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Atom History Essay An Atom is a basic unit of matter that consists of a dense‚ central nucleus surrounded by a cloud of negatively charged electrons. The Atom was theorized by a man named Democritus of Abdera‚ Thrace in between c.a 460 BC - ca. 370 B.C. Atom is derived from the Greek word “atomos” ‚ which means to be uncuttable. He had a theory that everything is composed of “atoms”‚ which he believed that these minuscule objects are indivisible‚ indestructible and have and always been in motion
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