A thermal expansion valve (often abbreviated as TEV, TXV or TX valve) is a component in refrigeration and air conditioning systems that controls the amount of refrigerant flow into the evaporator thereby controlling the superheating at the outlet of the evaporator. Thermal expansion valves are often referred to generically as "metering devices". Flow control, or metering, of the refrigerant is accomplished by use of a temperature sensing bulb filled with a similar gas as in the system that causes
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solution – • contains hydrogen ions and hydroxide ions in equal concentrations. Note: In the context of acid-base chemistry, the hydrogen ion usually is referred to as a proton because an atom of hydrogen contains one proton and one electron when it loses the electron during ion formation all that is left is the nucleus, which is one proton. © POGIL – 2005 Authored by Josephine Parlagreco and Robert Dayton Edited by Linda Padwa and David Hanson, Stony Brook University 1/4 Introduction to Acids and
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how electrons are arranged * # of electrons = the atomic # of atoms Sir James Chadwick: 1932 * Discovered in the nucleus another particle, neutron * Neutron has same weight as the proton * Neutron has no electrical charge * Nucleus is made up of protons and neutrons * # of protons is = to # of electrons, which is the atomic # of atom Atoms & Molecules * Atoms combine & arrange to form different compounds & molecules * Molecule: 2 or more atoms that
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many ways and processed in order to yield an NMR spectrum for the nucleus concerned. Chemical Shift describes the fact that all nuclei containing an odd number of protons and neutrons have something called a “spin” –a built-in type of movement which is also called resonance. This movement is slightly different for different protons in a given molecule, and can change depending on the chemical environment. The Zeeman Effect explains what happens when a spectral line—an emission or absorption
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reasonably complete experimental set of data supporting the (at that time new from 1911) Ernest Rutherford/Antonius Van den Broek concept of the atom, in which atomic number is understood as representing physically exactly the number of positive charges (protons) in a central atomic
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composed of elements, which are substances that cannot be broken down into other substances. Looking at Nitrogen, we can see that the atomic number is seven (number of protons in the nucleus), the symbol is N, and the atomic weight of Nitrogen is 14.01. Nitrogen is one of four elements that make up living cells. A Nitrogen atom has protons and neutron in the central nucleus with two electrons on the inside and four electrons on the outside. Electrons on the outer shell will interact electrons of atoms
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ability to do work -Metabolism- Chemical reactions in a cell that allows it to use energy -Element- A chemically pure substance that cannot not be broken down -Matter- anything that takes of space -Atom- smallest unit of an element -Proton- positively charged particle inside nucleus -Electron- negatively charged particle around nucleus -Neutron- uncharged particle inside nucleus -Nucleus- core of an atom -Covalent Bond- strong bond from the sharing of electrons between two
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the radius of the path, and b) the speed of the electron. Problem 4. A cyclotron designed to accelerate protons has a magnetic field of magnitude 0.45 T over a region of radius 1.2 m. What are a) the cyclotron frequency, and b) the maximum speed acquired by the protons? Problem 5. A cyclotron is designed to accelerate deuterium nuclei. (Deuterium has one proton and one neutron in its nucleus.) a) If the cyclotron uses a 2.0 T magnetic field, at what frequency should
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versa. 2. What are the potential benefits and risks in using nuclear tracers in medical diagnosis? 3. What type of nuclear reaction powers our Sun? The type of nuclear reaction that powers the sun is nuclear fusion (hydrogen nucleus and proton). 4. What form of indoor air pollution is the result of naturally occurring radioactive decay? Radon is a form of indoor air pollution resulting from naturally occurring radioactive decay. 5. Why must uranium be enriched in order to be
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definition can be extended to include charged atoms and molecules, so as to include plasmas (gases of ions) and electrolytes (ionic solutions), which are not obviously included in the atoms and molecules definition. Alternatively, one can adopt the protons Baryonic
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