FIRST PERIODICAL EXAM GRADE 7 NAME: SCORE: YEAR AND SECTION: DATE: I. MULTIPLE CHOICE. Circle the letter of the correct answer. 1. What is the set of procedures that can be used to explain and predict events or phenomena? A. Scientific discovery B. Scientific method C. Scientific notation D. Scientific thinking 2. Which of the following pairs of elements make up the salt compound? A. chlorine and oxygen B. oxygen and hydrogen C. sodium and chlorine D. sodium and hydrogen 3. What
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* Her Family & Childhood Marie Sklodowski was born on November 7‚ 1867 in Warsaw the capital of Poland. Both of her parents were school teachers‚ and they had high expectations for their five children (Zosia‚ Bronia‚ Jozef‚ Helena and Marie). Marie‚ her sisters‚ and brother all graduated with the highest grades in their class. The Sklodowski family was very learned and cultured‚ but they struggled financially. Poland was occupied by Russia and Germany. Many jobs were taken by these unwelcome foreigners
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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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Major Uses of Radioisotopes Americum-241 Used in many smoke detectors for homes and businesses…to measure levels of toxic lead in dried paint samples…to ensure uniform thickness in rolling processes like steel and paper production…and to help determine where oil wells should be drilled. Used to analyze metal alloys for checking stock‚ scrap sorting Cadmium-109 Calcium-47 Californium-252 Carbon-14 Cesuim-137 Chromium-51 Important aid to biomedical researchers studying
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Bequerel: discovered that uranium is radioactive Radioactivity = spontaneous emission of radiant E from an element as its nucleus decays. Radioactivity does not come from stable elements. 9. Marrie & Pierre Curie: Discovered 2 radioactive element Po(polonium) and Ra (Radioactive) 10. Ernest Rutherford: British scientist who discovered 3 kinds of radioactivity. Alpha: 2 plus charge & heaviest/ 3 is the slowest Beta: charge very light weight; fast Gamma: no charge (neutral) (no particles) Just lead
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uranium-238. Radon-220 is formed in the decay chain of thorium-232. It is radon-222 that most readily occurs in the environment. Atmospheric releases of radon-222 results in the formation of decay products that are radioisotopes of heavy metals (polonium‚ lead‚ bismuth) and rapidly attach to other airborne materials such as dust and other materials facilitating inhalation. The amount of radon in the soil depends on complex soil chemistry‚ that varies from one house to the next. Radon levels in the
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find out how the alpha particle would react against the thin foil. Geiger and Marsden constructed a lead box (to prevent radiation spreading all over the vacuum) with a hole on the center of the box‚ and inserted an alpha particle emitter (decaying polonium-214) inside the box. About five centimeters in front of the hole on the lead box was a gold foil with approximately 8.6x10-6 thick. The apparatus was then surrounded by zinc sulfide screen‚ which would
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(2011‚ December). Meet the Most Interesting Man in the World. Retrieved December 6‚ 2011‚ from http://www.wcax.com/story/16192523/meet-the-most-interesting-man-in-the-world Fröman‚ N. (1996‚ February 28). Marie and Pierre Curie and the Discovery of Polonium and Radium. Retrieved December 11‚ 2011‚ from Nobel Prize: http://www.nobelprize.org/nobel_prizes/physics/articles/curie/ IBM. (2011). Executive Officers. Retrieved December 10‚ 2011‚ from http://www.ibm.com/investor/governance/executive-officers
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Periodic Table Timeline http://www.history-timelines.org.uk/events-timelines/19-periodic-table... Periodic Table Timeline Timelines of Events History & Timelines Index Next Event Timeline>> Periodic Table Timeline This Chemistry Timeline has been developed to provide a ’snapshot’ of the famous people and events during this historical time period. Important dates in a fast‚ comprehensive‚ chronological‚ or date order providing an actual sequence of important past events which were
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The quote‚ “If you educate a boy‚ you educate an individual but if you educate a girl‚ you educate a nation” originated from an African proverb. It might have originated because of the societal roles of men and women‚ society’s expectations‚ and the contribution each gender has made to the community. Both men and women have educated the nation in many different ways‚ either by contributing to the society‚ or to their families. Hence‚ I disagree with this quote‚ as not all men have never educated
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