Proxies – measureable records that can provide data on factors such as temperature‚ ice cover‚ and precipitation. Isotopes – A form of an element in which the atoms have more (or less) than the usual number of neutrons. Isotopes of a given element have identical chemical properties‚ but differ in mass (weight) as a result of the superfluity (or deficiency) of neutrons. Many isotopes are unstable and radioactive. Milankovitch Cycles – A cycle of major oscillations in the Earth’s orbit‚ taking place
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Identification and Production of Materials ================================ Ethene‚ Polymers and Ethanol ================================ Catalytic Cracking Oil refineries need to balance their outputs of various products (petrol‚ diesel‚ fuel oil‚ etc.) to match the demands of the marketplace. Catalytic cracking is the process in which high molecular weight (high boiling point) fractions from crude oil are broken into lower molecular weight (lower boiling point) substances in order to increase
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Atoms and the Periodic Table Chapter 2 Atoms and the Periodic Table / Elements and the Periodic Table * An element is a pure substance that cannot be broken down into simpler substances by a chemical reaction. * Each element is identified by a one- or two-letter symbol. * Elements are arranged in the periodic table. * The position of an element in the periodic table tells us much about its chemical properties. Atoms and the Periodic Table / Elements and the Periodic
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Chapter 5: Nuclear Power 1. 2. 3. 4. 5. 6. Working principle Nuclear reactors Detection and safety issues Radioactive wastes treatment Comparison to other powers Possible alternatives 1 Do you know? 2 Mass & Atomic Numbers Isotopes All of the following are possible sources of radiation except a. background radiation from the Earth’s crust. b. nuclear waste. c. medical & dental X-rays. d. distilled water. A Z X Symbol 12 13 14 6 6 6 C
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electrons‚ protons and neutrons of the following e- p+ n a.) Oxygen - 8 8 b.) Cesium - 55 55 c.) Argon - 18 18 d.) Uranium - 92 92 e.) Copper - 29 29 2. Calculate the atomic mass of sulfur from its natural isotope. f.) Sulfur-36 g.) Sulfur-32 h.) Sulfur-33 i.) Sulfur-34 3. Complete this table. Symbol of Elements | Atomic Number | Atomic Mass | # of protons | # of Electrons | # of Neutrons | Sc | 21 | | 21 | 21 | 24 | Zn | 30
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Wea`am Mohammad Al-jarie Dr. mokhleed zaza physics Medical applications of x-ray Introduction: X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers‚ corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) X-rays up to about 10 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays‚ and from about 10 to 120 keV (0.10 to 0.01 nm wavelength) as "hard" X-rays‚ due
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white Electron Shell Configuration Number of Energy Levels: Three (3) First Energy Level: Two (2) Second Energy Level:Eight (8) Third Energy Level: Three (3) Isotopes In total‚ Aluminium has approximately 23 known isotopes ranging from Al-21 to Al-43‚ with two of these isotopes occurring naturally on Earth. Aluminium isotope Al-26 with a half-life of 730‚ 000 years‚ is only found naturally on Earth in very small traces‚ and is formed by the cosmic-ray bombardment of argon in the Earth’s atmosphere
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Elemental Exposure-General Truisms Childhood Lead Poisoning Why you might be smarter than your parents • Most are not toxic • Nutritional = less toxic (Zn‚ Cd) Noel Stanton WI State Lab of Hygiene 2601 Agriculture Drive PO Box 7996 Madison WI 53707 (608) 224-6251 nvstox@mail.slh.wisc.edu – Homeostasis • Abundance = toxicity • Every truism has exceptions Speciation Considerations • Can greatly influence toxicity • Ability to differentiate limited‚ improving – Cr+3
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Bromine’s physical state is a liquid‚ and it’s density is 3.122 g/cm^3. Bromine has a boiling point of 137.8ºF‚ which is also 58.8ºC. isotopes (Br-80)- 69-97 It’s melting point is 19ºF‚ also is -7.2ºC. Bromine is not very reactive as fluorine or chlorine but it’s way more reactive than iodine. Bromine is a nonmetal‚ and it’s a natural element. Bromine is known to be a very dense reddish brown toned liquid when formed compounds with elements such as chlorine‚ it works as a bleaching agent. It evaporates
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periodic table. 7. No two different elements will have the ____________________. What is a valence electron? _____________________________________ 8. The _____________ of an element is the average mass of an element’s naturally occurring atoms and isotopes. 9. The _____________________ of an element is the total number of protons and neutrons in the ___________________ of the atom. 10. The mass number is used to calculate the number of ____________ in one atom of an element. In order to calculate the
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