Structural Functionalism and Yard Sales

Actinides (Actinide Series) Element Properties

Actinides (Actinide Series) Element Properties At the bottom of the periodic table, there is a special group of radioactive metallic elements. These elements have interesting properties and play a key role in nuclear chemistry. Actinides Definition The actinides or actinoids are a set of radioactive elements on the periodic table, usually considered ranging from atomic number 89 to atomic number 103. Location of the Actinides The modern periodic table has two rows of elements below the main body of the table. The actinides are the elements in the bottom row. The top row is the lanthanide series. The reason these two rows of elements are placed below the main table is that they dont fit in the design without making the table confusing and very wide. However, these two rows of elements are metals, sometimes considered a subset of the transition metals group. In fact, the lanthanides and actinides are sometimes called the inner transition metals, referring to their properties and position on the table. Two ways of including the lanthanides and actinides within a periodic table are to include those elements in their corresponding rows with the transition metals (makes the table wider) or ballooning them out to make a three-dimensional table. List of Elements in the Actinide Series There are 15 actinide elements. The electronic configurations of the actinides utilize the f sublevel, with the exception of lawrencium (a d-block element). Depending on your interpretation of the periodicity of the elements, the series begins with actinium or thorium, continuing to lawrencium. The usual list of elements in the actinide series is: Actinium (Ac)Thorium (Th)Protactinium (Pa)Uranium (U)Neptunium (Np)Plutonium (Pu)Americium (Am)Curium (Cm)Berkelium (Bk)Californium (Cf)Einsteinium (Es)Fermium (Fm)Mendelevium (Md)Nobelium (No)Lawrencium (Lr) Actinide Abundance The only two actinides found in appreciable quantities in the Earths crust are thorium and uranium. Small quantities of plutonium and neptunium are present in uranium orders. Actinium and protactinium occur as decay products of certain thorium and uranium isotopes. The other actinides are considered synthetic elements. If they occur naturally, it is part of a decay scheme of a heavier element. Common Properties of the Actinides Actinides share the following common properties: All are radioactive. These elements have no stable isotopes.Actinides are highly electropositive.The metals tarnish readily in air. These elements are pyrophoric (spontaneously ignite in air), particularly as finely divided powders.Actinides are very dense metals with distinctive structures. Numerous allotropes may be formed (plutonium has at least 6 allotropes!). The exception is actinium, which has fewer crystalline phases.They react with boiling water or dilute acid to release hydrogen gas.Actinide metals tend to be fairly soft. Some can be cut with a knife.These elements are malleable and ductile.All of the actinides are paramagnetic.All of these elements are silver-colored metals that are solid at room temperature and pressure.Actinides combine directly with most nonmetals.The actinides successively fill the 5f sublevel. Many actinide metals have properties of both d block and f block elements.Actinides display several valence states (typically more than the lanthanides). Most a re prone to hybridization. The actinides (An) may be prepared by reduction of AnF3  or AnF4  with vapors of Li, Mg, Ca, or Ba at 1100 - 1400 °C. Actinide Uses For the most part, we dont encounter these radioactive elements much in daily life. Americium is found in smoke detectors. Thorium is found in gas mantles. Actinium is used in scientific and medical research as a neutron source, indicator, and gamma source. Actinides may be used as dopants to make glass and crystals luminescent. The bulk of actinide use goes to energy production and defense operations. The primary use of the actinide elements is as nuclear reactor fuel and for the production of nuclear weapons. The actinides are favored for these reactions because they readily undergo nuclear reactions, releasing incredible amounts of energy. If the conditions are right, the nuclear reactions may become chain reactions. References E. Fermi (1934). Possible Production of Elements of Atomic Number Higher than 92.  Nature.  133  (3372): 898–899.Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 1230–1242.Theodore Gray (2009).  The Elements: A Visual Exploration of Every Known Atom in the Universe. New York: Black Dog Leventhal Publishers. p.  240.

Home work 2 (envi 423) Read the attachment carefully Essay

Home work 2 (envi 423) Read the attachment carefully - Essay Example Germany ($3.383 trillion), Japan ($5.88 trillion), and the United States ($16.02 trillion), it is safe to say that the Arab League members are not as rich as these â€Å"super power† countries (Central Intelligence Agency). A lot of the recent commotion in the Middle East is about Israel’s opposition of letting Occupied Palestine (referred to as West Bank or Gaza Strip) become an independent state because the territory that Palestine wants to occupy would pose a great loss to the resources of Israel and its citizens. According to the CIA World Fact Book, Israel’s 2012 GDP is $254 billion while Palestine’s GDP is merely 2.6% of Israel’s ($ 6.641 billion). 2.6% of a country’s GDP is not such a big loss if it will result to peace and finally ending the bloodshed between Israel, Palestine and their allies (Central Intelligence Agency). Ethnocentric mentality and greed are the culprits behind these twisted assumptions that many people from Western countries have. But in the end, it is neither the individual citizens of the Middle East countries nor that of the West benefit from all these politics and turmoil surrounding Middle East Oil. The ordinary citizens carry the costs while corrupt government officials and top company executives get insanely rich. The issue with Middle East Oil extends beyond politics and power, the real deal is in the equal distribution of resources on all levels of society across the different countries, whether oil exporting or not (Central Intelligence Agency). Central Inteligence Agency. The World Fact Book: Field Listing: GDP (Official Exchange Rate). 2012. Web. 27 January 2014.