Wednesday, March 18, 2020
The Code of Hammurabi The overall success in any society largely depends on the order and the stability in that society. Of course, the prosperity of any particular civilization is based on the stability of the economy in that civilization. But the laws and the basic moral principles have a huge influence on economy and on overall welfare of the people. The laws should include sections on social, moral, religious, civil, commercial, and criminal law. The laws reflect the level of development of the society at the specific period of time. Laws cannot be perfect and they cannot equally protect everyone, but the societies that live by the laws have numerous advantages over those that don't. The laws make a society civilized.Code of laws of HammurabiHammurabi was the ruler of the Old Babylonian Empire, during the 18th century BCE. He was a smart military leader and legislator. He developed the first known legal code in history, Hammurabi's Code. He clearly understood the importance of the jurisprudence system and even put his code of laws among his most significant accomplishments. Hammurabi made his set of laws public, clearly explaining what was required of the citizens, and what the punishments were for not following these laws. Although the system of justice was not applied equally to all during the time of Hammurabi, the laws were fair, considering the times and the society of that time. One of the most well known aspects of the code is the principle "an eye for an eye and a tooth for a tooth". So, for example, if someone has plucked out a neighbor's eye he would have his eye removed.Unfortunately, just like in any other civilization at that time, lower classes of people were not treated equally to the higher classes of aristocrats. Of course, no one could get away...
Sunday, March 1, 2020
Helium Facts (Atomic Number 2 or He) Helium is atomic number 2 on the periodic table, with the element symbol He. It is a colorless, flavorless gas, best known for its use in filling floating balloons. Here is a collection of facts about this lightweight, interesting element: Helium Element Facts Helium Atomic Number: 2 Helium Symbol: He Helium Atomic Weight: 4.002602(2) Helium Discovery: Janssen, 1868, some sources say Sir William Ramsey, Nils Langet, P.T. Cleve 1895 Helium Electron Configuration: 1s2 Word Origin: Greek: helios, sun. Helium was first detected as a new spectral line during a solar eclipse, so it is named for the Greek Titan of the Sun. Isotopes: 9 isotopes of helium are known. Only two isotopes are stable: helium-3 and helium-4. While the isotopic abundance of helium varies depending on geographical location and source, 4He accounts for nearly all of the natural helium. Properties: Helium is a very light, inert, colorless gas. Helium has the lowest melting point of any element. It is the only liquid that cannot be solidified by lowering the temperature. It remains liquid down to absolute zero at ordinary pressures, but can be solidified by increasing the pressure. The specific heat of helium gas is unusually high. The density of helium vapor at the normal boiling point is also very high, with the vapor expanding greatly when heated to room temperature. Although helium normally has a valence of zero, it has a weak tendency to combine with certain other elements. Uses: Helium is widely used in cryogenic research because its boiling point is near absolute zero. It is used in the study of superconductivity, as an inert gas shield for arc welding, as a protective gas in growing silicon and germanium crystals and producing titanium and zirconium, for pressuring liquid fuel rockets, for use in magnetic resonance imaging (MRI), as a cooling medium for nuclear reactors, and as a gas for supersonic wind tunnels. A mixture of helium and oxygen is used as an artificial atmosphere for divers and others working under pressure. Helium is used for filling balloons and blimps. Sources: Except for hydrogen, helium is the most abundant element in the universe. It is an important component in the proton-proton reaction and the carbon cycle, which account for the energy of the sun and stars. Helium is extracted from natural gas. In fact, all natural gas contains at least trace quantities of helium. The fusion of hydrogen into helium is the sources of a hydrogen bombs energy. Helium is a disintegration product of radioactive substances, so it is found in ores of uranium, radium, and other elements. Most of Earths helium dates back to the planets formation, although a small amount falls to Earth within cosmic dust and some is produced via beta decay of tritium. Health Effects: Helium serves no biological function. Trace amounts of the element are found in human blood. While helium is considered to be non-toxic, it displaces oxygen so inhaling it can lead to hypoxia or asphyxiation. Fatalities from inhaling helium are rare. Liquid helium is a cryogenic liquid, so risks include frostbite from exposure and explosion from expansion if the liquid is stored in a sealed container. The mixture of helium and oxygen (heliox) can cause high-pressure nervous syndrome, however the addition of nitrogen can remedy the issue. Compounds: Because a helium atom has a valence of zero, it has extremely low chemical reactivity. However, unstable compounds called excimers can be formed when electricity is applied to the gas. HeH is stable in its ground state, but it is the strongest known Bronsted acid, capable of protonating any species it encounters. Van der Waals compounds form with cryogenic helium gas, such as LiHe. Element Classification: Noble Gas or Inert Gas Usual Phase: gas Density (g/cc): 0.1786 g/L (0 Ã °C, 101.325 kPa) Liquid Density (g/cc): 0.125 g/mL (at its boiling point) Melting Point (Ã °K): 0.95 Boiling Point (Ã °K): 4.216 Critical Point: 5.19 K, 0.227 MPa Atomic Volume (cc/mol): 31.8 Ionic Radius: 93 Specific Heat (20Ã °C J/g mol): 5.188 Heat of Fusion: 0.0138 kJ/mol Evaporation Heat (kJ/mol): 0.08 First Ionizing Energy (kJ/mol): 2361.3 Lattice Structure: Hexagonal Lattice Constant (Ãâ¦): 3.570 Lattice C/A Ratio: 1.633 Crystal Structure: close-packed hexagonal Magnetic Ordering: diamagnetic CAS registry number: 7440-59-7 Quiz: Ready to test your helium facts knowledge? Take the Helium Facts Quiz. References Meija, J.; et al. (2016). Atomic weights of the elements 2013 (IUPAC Technical Report). Pure and Applied Chemistry. 88 (3): 265Ã¢â¬â91. doi:10.1515/pac-2015-0305Shuen-Chen Hwang, Robert D. Lein, Daniel A. Morgan (2005). Noble Gases. Kirk Othmer Encyclopedia of Chemical Technology. Wiley. pp. 343Ã¢â¬â383. doi:10.1002/0471238961.0701190508230114.a01.Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4. Return to the Periodic Table