They gave that name to this element because it was the first element which produced artificially. It means‚ it is the first element in the periodic table which is manmade. They made it in the University of Palermo laboratory. Technetium is a radioactive metal with silvery grey colour. Its melting point is 2157oC and its boiling point is 4265oC. Its liquid range is 2108 K. It means the difference between melting point and boiling point. Technetium is solid in the room temperature. It’s density is
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Most elements have isotopes. For stable isotopes‚ an interesting plot arises when the number of neutrons is plotted versus the number of protons. Because the plot shows only the stable isotopes‚ this graph is often called the Nuclear Belt of Stability. The plot indicates that lighter nuclides (isotopes) are most stable when the neutron/proton ratio is 1/1. This is the case with any nucleus that has up to 20 protons. As the atomic number increases beyond 20‚ a different trend becomes apparent. In
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Nuclear Advancements After the Manhattan Project When the first atomic bomb was detonated in Alamogordo New Mexico on June 16‚ 1945‚ all the scientists involved in the Manhattan Project understood the great destructive power of radio-active isotopes. Although the atomic bomb was a very destructive force our world would not be as good without it. Because of the government funding involved in the project coupled with the need for an atom bomb‚ much research that otherwise may not have occurred
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Unit 2 Lesson 3 The kinetic theory of matter explains that matter is made up of particles‚ which are in constant motion resulting in the different states of matter. Matter is made of constantly moving particles‚ which tells us how the matter in solids‚ liquids‚ and gases behaves. When molecules bump into each other‚ they do not gain or lose energy‚ they only transfer it‚ so there is no net energy change (law of the conservation of energy). In a solid‚ molecules vibrate in a fixed position
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nuclear fission currently holds the upper hand as a nuclear fusion reactor is yet to be formed. Nuclear fission occurs when a stable isotope is hit by a neutron causing the isotope to absorb it‚ making it unstable and splitting it apart releasing huge amounts of energy. Nuclear fission is currently used for nuclear weapons and nuclear reactors‚ examples of isotopes that can undergo the process are Uranium235 and Plutonium 239. Advantages of Nuclear fission are that it doesn’t release carbon emissions
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Radioactive Pollution Radioactivity is a phenomenon of spontaneous emission of proton (a-particles)‚ electrons (ß-particles) and ?-rays (short wave electromagnetic waves) due to disintegration of atomic nuclei of some elements. These cause radioactive pollution. Radiations are of two types ionising and non-ionising. Non-ionising radiations affect only those components which absorb them and have low penetrability. Ionising radiations have high penetration power and cause breakage of macro molecules
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to the human diet. 2.3 Distinguish between the size‚ location‚ and properties of protons‚ electrons‚ and neutrons. 2.3 Define the atomic number and mass number of an atom. 2.3 Define an isotope and explain what makes some isotopes radioactive. 2.4 Describe the uses and dangers of radioactive isotopes. Chemical Bonds 2.5 Explain how the electron configuration of an atom influences its chemical behavior. 2.6–2.8 Distinguish between covalent bonds‚ nonpolar polar covalent bonds‚ polar
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1 1 The nucleus of one of the isotopes of nickel is represented by 60 Ni. 28 Which line in the table correctly describes a neutral atom of this isotope? number of protons A B C D 28 28 60 60 number of neutrons 32 60 28 32 number of orbital electrons 28 28 28 32 2 A nucleus of bohrium x Bh decays to mendelevium y emissions. bohrium x Bh → dubnium + α y → lawrencium + α 255 Md 101 by a sequence of three α-particle → mendelevium 255 Md + α 101 How many neutrons are there in a
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forms when one of the following rocks is metamorphosed? Limestone In which of the following sedimentary rocks would it be easiest to determine the type of rocks from which the sediment was derived? Conglomerates Which of the following radioactive isotopes is the most useful for dating very young wood and charcoal? Radiocarbon The prograde part of a metamorphic P-T path occurs during _________________. Burial and heating Someone brings a piece of wood from Noah’s Arc and asks you to date
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_____Alvaro_________________________________ Date: ________________________ Student Exploration: Element Builder Vocabulary: atom‚ atomic number‚ electron‚ electron dot diagram‚ element‚ energy level‚ ion‚ isotope‚ mass number‚ neutron‚ nucleus‚ periodic table‚ proton‚ radioactive‚ valence electrons Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. What are some of the different substances that make up a pizza? _____________________ _________________________________________________________________________
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