Iodine Element Facts - Periodic Table

Iodine Element Facts - Periodic Table Iodine  Basic Facts Atomic Number: 53 Iodine Symbol: I Atomic Weight: 126.90447 Discovery: Bernard Courtois 1811 (France) Electron Configuration: [Kr] 4d10 5s2 5p5 Word Origin: Greek iodes, violet Isotopes: Twenty-three isotopes of iodine are known. Only one stable isotope is found in nature, I-127. Properties Iodine has a melting point of 113.5 °C, a boiling point of 184.35 °C, a specific gravity of 4.93 for its solid state at 20 °C, a gas density of 11.27 g/l, with a valence of 1, 3, 5, or 7. Iodine is a lustrous blue-black solid which volatizes at room temperature into a violet-blue gas with an irritating odor. Iodine forms compounds with many elements, but it is less reactive than the other halogens, which will displace it. Iodine also possesses some properties typical of metals. Iodine is only slightly soluble in water, although it dissolves readily in carbon tetrachloride, chloroform, and carbon disulfide, forming purple solutions. Iodine will bind to starch and color it deep blue. Although iodine is essential for proper nutrition, care is needed when handling the element, as skin contact can cause lesions and the vapor is highly irritating to the eyes and mucous membranes. Uses The radioisotope I-131, with a half-life of 8 days, has been used to treat thyroid disorders. Insufficient dietary iodine leads to the formation of a goiter. A solution of iodine and KI in alcohol is used to disinfect external wounds. Potassium iodide is used in photography. Sources Iodine is found in the form of iodides in seawater and in the seaweeds which absorb the compounds. The element is found in Chilean saltpeter, and nitrate-bearing earth (caliche), brackish waters from salt wells and oil wells, and in brines from old sea deposits. Ultrapure iodine may be prepared by reacting potassium iodide with copper sulfate. Element Classification: Halogen Iodine Physical Data Density (g/cc): 4.93 Melting Point (K): 386.7 Boiling Point (K): 457.5 Appearance: shiny, black nonmetallic solid Atomic Volume (cc/mol): 25.7 Covalent Radius (pm): 133 Ionic Radius: 50 (7e) 220 (-1e) Specific Heat (20 °C J/g mol): 0.427 (I-I) Fusion Heat (kJ/mol): 15.52 (I-I) Evaporation Heat (kJ/mol): 41.95 (I-I) Pauling Negativity Number: 2.66 First Ionizing Energy (kJ/mol): 1008.3 Oxidation States: 7, 5, 1, -1 Lattice Structure: Orthorhombic Lattice Constant (Ã…): 7.720 References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Langes Handbook of Chemistry (1952), CRC Handbook of Chemistry Physics (18th Ed.)

Causes of the French Indian War

Causes of the French Indian War In 1748, the War of the Austrian Succession came to a conclusion with the Treaty of Aix-la-Chapelle. During the course of the eight-year conflict, France, Prussia, and Spain had squared off against Austria, Britain, Russia, and the Low Countries. When the treaty was signed, many of the underlying issues of the conflict remained unresolved including those of expanding empires and Prussias seizure of Silesia. In the negotiations, many captured colonial outposts were returned to their original owners, such as Madras to the British and Louisbourg to the French, while the trading rivalries that had helped cause the war were ignored. Due to this relatively inconclusive result, the treaty was considered by many to a peace without victory with international tensions remaining high among the recent combatants. The Situation in North America Known as King Georges War in the North American colonies, the conflict had seen colonial troops mount a daring and successful attempt to capture the French fortress of Louisbourg on Cape Breton Island. The return of the fortress was a point of concern and ire among the colonists when peace was declared. While the British colonies occupied much of the Atlantic coast, they were effectively surrounded by French lands to the north and west. To control this vast expanse of territory extending from the mouth of the St. Lawrence down to the Mississippi Delta, the French built a string of outposts and forts from the western Great Lakes down to the Gulf of Mexico. The location of this line left a wide area between the French garrisons and the crest of the Appalachian Mountains to the east. This territory, largely drained by the Ohio River, was claimed by the French but was increasingly filling with British settlers as they pushed over the mountains. This was largely due to the burgeoning population of the British colonies which in 1754 contained around 1,160,000 white inhabitants as well as another 300,000 slaves. These numbers dwarfed the population of New France which totaled around 55,000 in present-day Canada and another 25,000 in other areas. Caught between these rival empires were the Native Americans, of which the Iroquois Confederacy was the most powerful. Initially consisting of the Mohawk, Seneca, Oneida, Onondaga, and Cayuga, the group later became the Six Nations with the addition of the Tuscarora. United, their territory extended between the French and British from the upper reaches of the Hudson River west into the Ohio basin. While officially neutral, the Six Nations were courted by both European powers and frequently traded with whichever side was convenient. The French Stake Their Claim In an effort to assert their control over the Ohio Country, the governor of New France, the Marquis de La Galissonià ¨re, dispatched Captain Pierre Joseph Cà ©loron de Blainville in 1749 to restore and mark the border. Departing Montreal, his expedition of around 270 men moved through present-day western New York and Pennsylvania. As it progressed, he placed lead plates announcing Frances claim to the land at the mouths of several creeks and rivers. Reaching Logstown on the Ohio River, he evicted several British traders and admonished the Native Americans against trading with anyone but the French. After passing present-day Cincinnati, he turned north and returned to Montreal. Despite Cà ©lorons expedition, British settlers continued to push over the mountains, especially those from Virginia. This was backed by the colonial government of Virginia who granted land in the Ohio Country to the Ohio Land Company. Dispatching surveyor Christopher Gist, the company began scouting the region and received permission from the Native Americans to fortify the trading post at Logstown. Aware of these increasing British incursions, the new governor of New France, the Marquis de Duquesne, sent Paul Marin de la Malgue to the area with 2,000 men in 1753 to built a new series of forts. The first of these was built at Presque Isle on Lake Erie (Erie, PA), with another twelve miles south at French Creek (Fort Le Boeuf). Pushing down the Allegheny River, Marin captured the trading post at Venango and built Fort Machault. The Iroquois were alarmed by these actions and complained to British Indian agent Sir William Johnson. The British Response As Marin was constructing his outposts, the lieutenant governor of Virginia, Robert Dinwiddie, became increasingly concerned. Lobbying for the building of a similar string of forts, he received permission provided that he first assert British rights to the French. To do so, he dispatched young Major George Washington on October 31, 1753. Traveling north with Gist, Washington paused at the Forks of the Ohio where the Allegheny and Monongahela Rivers came together to form the Ohio. Reaching Logstown, the party was joined by Tanaghrisson (Half King), a Seneca chief who disliked the French. The party ultimately reached Fort Le Boeuf on December 12 and Washington met with Jacques Legardeur de Saint-Pierre. Presenting an order from Dinwiddie requiring the French to depart, Washington received a negative reply from Legarduer. Returning to Virginia, Washington informed Dinwiddie of the situation. First Shots Prior to Washingtons return, Dinwiddie dispatched a small party of men under William Trent to begin building a fort at the Forks of the Ohio. Arriving in February 1754, they constructed a small stockade but were forced out by a French force led by Claude-Pierre Pecaudy de Contrecoeur in April. Taking possession of the site, they began constructing a new base dubbed Fort Duquesne. After presenting his report in Williamsburg, Washington was ordered to return to the forks with a larger force to aid Trent in his work. Learning of the French force en route, he pressed on with the support of Tanaghrisson. Arriving at Great Meadows, approximately 35 miles south of Fort Duquesne, Washington halted as he knew he was badly outnumbered. Establishing a base camp in the meadows, Washington began exploring the area while waiting for reinforcements. Three days later, he was alerted to the approach of a French scouting party. Assessing the situation, Washington was advised to attack by Tanaghrisson. Agreeing, Washington and approximately 40 of his men marched through the night and foul weather. Finding the French camped in a narrow valley, the British surrounded their position and opened fire. In the resulting Battle of Jumonville Glen, Washingtons men killed 10 French soldiers and captured 21, including their commander Ensign Joseph Coulon de Villiers de Jumonville. After the battle, as Washington was interrogating Jumonville, Tanaghrisson walked up and struck the French officer in the head killing him. Anticipating a French counterattack, Washington fell back to Great Meadows and built a crude stockade known as Fort Necessity. Though reinforced, he remained outnumbered when Captain Louis Coulon de Villiers arrived at Great Meadows with 700 men on July 1. Beginning the Battle of Great Meadows, Coulon was able to quickly compel Washington to surrender. Allowed to withdraw with his men, Washington departed the area on July 4. The Albany Congress While events were unfolding on the frontier, the northern colonies were becoming increasingly concerned about French activities. Gathering in the summer of 1754, representatives from the various British colonies came together in Albany to discuss plans for mutual defense and to renew their agreements with the Iroquois which were known as the Covenant Chain. In the talks, Iroquois representative Chief Hendrick requested the re-appointment of Johnson and expressed concern over British and French activities. His concerns were largely placated and the Six Nations representatives departed after the ritual presentation of presents. The representatives also debated a plan for uniting the colonies under a single government for mutual defense and administration. Dubbed the Albany Plan of Union, it required an Act of Parliament to implement as well as the support of the colonial legislatures. The brainchild of Benjamin Franklin, the plan received little support among the individual legislatures and was not addressed by Parliament in London. British Plans for 1755 Though war with France had not been formally declared, the British government, led by the Duke of Newcastle, made plans for a series of campaigns in 1755 designed to reduce French influence in North America. While Major General Edward Braddock was to lead a large force against Fort Duquesne, Sir William Johnson was to advance up Lakes George and Champlain to capture Fort St. Frà ©dà ©ric (Crown Point). In addition to these efforts, Governor William Shirley, made a major general, was tasked with reinforcing Fort Oswego in western New York before moving against Fort Niagara. To the east, Lieutenant Colonel Robert Monckton was ordered to capture Fort Beausà ©jour on the frontier between Nova Scotia and Acadia. Braddocks Failure Designated the commander-in-chief of British forces in America, Braddock was convinced by Dinwiddie to mount his expedition against Fort Duquesne from Virginia as the resulting military road would benefit the lieutenant governors business interests. Assembling a force of around 2,400 men, he established his base at Fort Cumberland, MD before pushing north on May 29. Accompanied by Washington, the army followed his earlier route towards the Forks of the Ohio. Slowly plodding through the wilderness as his men cut a road for the wagons and artillery, Braddock sought to increase his speed by rushing forward with a light column of 1,300 men. Alerted to Braddocks approach, the French dispatched a mixed force of infantry and Native Americans from Fort Duquesne under the command of Captains Lià ©nard de Beaujeu and Captain Jean-Daniel Dumas. On July 9, 1755, they attacked the British in the Battle of the Monongahela (Map). In the fighting, Braddock was mortally wounded and his army routed. Defeated, the British column fell back to Great Meadows before retreating towards Philadelphia. Mixed Results Elsewhere To the east, Monckton had success in his operations against Fort Beausà ©jour. Beginning his offensive on June 3, he was in a position to begin shelling the fort ten days later. On July 16, British artillery breached the forts walls and the garrison surrendered. The capture of the fort was marred later that year when Nova Scotias governor, Charles Lawrence, began expelling the French-speaking Acadian population from the area. In western New York, Shirley moved through the wilderness and arrived at Oswego on August 17. Approximately 150 miles short of his goal, he paused amid reports that French strength was massing at Fort Frontenac across Lake Ontario. Hesitant to push on, he elected to halt for the season and began enlarging and reinforcing Fort Oswego. As the British campaigns were moving forward, the French benefited from knowledge of the enemys plans as they had captured Braddocks letters at Monongahela. This intelligence led to French commander Baron Dieskau moving down Lake Champlain to block Johnson rather than embarking on a campaign against Shirley. Seeking to attack Johnsons supply lines, Dieskau moved up (south) Lake George and scouted Fort Lyman (Edward). On September 8, his force clashed with Johnsons at the Battle of Lake George. Dieskau was wounded and captured in the fighting and the French were forced to withdraw. As it was late in the season, Johnson remained at the southern end of Lake George and began construction of Fort William Henry. Moving down the lake, the French retreated to Ticonderoga Point on Lake Champlain where they completed construction of Fort Carillon. With these movements, campaigning in 1755 effectively ended. What had begun as a frontier war in 1754, would explode into a global conflict in 1756.