Atom

An electron vacancy is created and is further filled by an electron from the higher shell and thus an X-ray is emitted to balance the difference in energy between the two electrons. The detector placed on the energy dispersive spectroscope apparatus measures the number of emitted X-rays and their energies. Energy of the X-ray is characteristics of the element from which X-ray is emitted. A spectrum of the relative counts of the detected X-rays is obtained and evaluated for quantitative…

Page 1 : http://mw2.concord.org/public/part2/intromacro/page1.cml 1. The individual DNA strands, which are macromolecules, are seen most clearly at 10 to the power of (a) -3 (b) +4 (c) -8 (d) -23 My answer is (c) (2:16:56 PM) 2. How many powers of ten are there between the DNA strands and you? Hint. (a) 3 (b) 6 (c) 8 (d) 12 My answer is (c) (2:17:22 PM) Page 2 : http://mw2.concord.org/public/part2/intromacro/page2.cml 1. Which of the following elements can be found in all four…

Chlorine is the second to lightest member of the halogen elements. It is in Group 17 (Group VIIA) and period 3 of the periodic table. The element symbol for Chlorine is Cl. Chlorine is a greenish yellow gas that is corrosive, toxic and can be irritating to the eyes and respiratory system. Chlorine is a nonmetal that has the atomic mass of 35.45 amu. It has a melting point of -100.98 degrees Celsius and a boing point of -34.6 degrees Celsius. However, at room temperature it is a gas. Chlorine…

Calibration 1: Text Cyclohexane is a six carbon cyclic alkane that is unusually stable compared to other cyclic alkanes. This stability can be seen by examining cyclohexane in its chair conformation. Since cyclohexane consists of all sp3 hybridized carbons, it ideally exists with 109.5-degree bond angles. If cyclohexane were planar, it would be forced to have 120-degree angels, and would therefore have angle strain. However, cyclohexane chair conformations are almost completely free of angle…

Lithium is an element with the atomic number 3 on the periodic table. Its atomic symbol is Li. Lithium belongs in the most reactive group on the periodic table which is called alkali metal. Lithium under standard conditions is the lightest metal it is also one of the least dense solids. Lithium has an atomic mass of 6.94 and density of 0.534. Lithium is a soft silver white looking metal. Lithium melts at 357 degrees and boils at a temper of 2426 degrees. Thanks to lithium's ability to reach…

Hydrogen is an Alkali earth metal in group 1 on the periodic table. Hydrogen has an atomic mass of 1 and an atomic number of 1. Hydrogen has 1 VALENCE electron and 1 neutron. It has 1 ring, because it’s in period 1. Hydrogens state of matter is gas. Lithium is a Alkali Earth Metal on the Periodic Table. Lithium's state or matter is solid. Lithium has a atomic number of 3 and an atomic mass of 7 when rounded. It has 1 valence electron around its nucleus and 4 neutrons in the nucleus. Lithium has…

Introduction The reaction of Hydro Chloric Acid with Aluminum is exothermic and very dynamic. The Hydrogen produced at such temperatures can easily explode by combining with the oxygen of the atmosphere. This reaction is known as a single displacement reaction because aluminum switches with the hydrogen. When aluminum is placed in a beaker of hydrochloric acid, the reaction produces hydrogen gas and aqueous aluminum chloride. The balanced chemical equation for the reaction is 2Al + 6HCl =…

DISCUSSION It is clear from the very low fraction of “head-to-head” linkages that this reaction is far less energetically favorable than the “head-to-tail” reaction, which occurs normally. The head-to-tail arrangement is preferred energetically due to steric and resonance effects. When the radical attacks the fourth (double-bonded) carbon, the new radical that is produced is more stable, as it may participate in resonance with the neighboring oxygen. Conversely, when the radical attacks the…

Photography dates back to 1839 as a result of the camera obscura. The camera obscura was a photographic medium that captured beautiful pictures, drawings, objects, still life and any views. Louis Jacques Mande Daguerre and William Henry Fox Talbot invented separate processes in London and Paris called the daguerreotype and the calotype. They both implemented the camera obscura to make their inventions. Both Daguerre and Talbot were passionate about and envisioned reproducing nature into…

Percentage yield The ratio between the actual yield and theoretical yield multiplied by 100 is called the percentage yield. Percentage yield demonstrates the percentage of theoretical that was gained from the end product in a reaction. The percentage yield is calculated using this equation: Percentage Yield =(Mass of actual yield)/(Mass of theoretical yield) ×100. The mass of actual yield is the mass of the end product that was gained from the experiment. The actual yield is the amount of…