Chemical Change Examples in Chemistry

Chemical Change Examples in Chemistry Chemical changes involve chemical reactions and the creation of new products. Typically, a chemical change is irreversible. In contrast, physical changes do not form new products and are reversible. Some Common Chemical Changes The rusting of ironCombustion (burning) of woodThe metabolism of food in the bodyMixing an acid and a base, such as hydrochloric acid (HCl) and sodium hydroxide (NaOH)Cooking an eggDigesting sugar with the amylase in salivaMixing baking soda and vinegar to produce carbon dioxide gasBaking a cakeElectroplating a metalUsing a chemical batteryThe explosion of fireworksRotting bananasGrilling a hamburgerMilk going sour Less-familiar chemical reactions are also examples of chemical changes. While its not always easy to tell a chemical change has occurred (as opposed to a physical change), there are some telltale signs. Chemical changes may cause a substance to change color, change temperature, produce bubbles, or (in liquids) produce a precipitate. Chemical changes can also be considered to be any phenomenon that allows a scientist to measure  chemical properties.

History of Newspapers In America

History of Newspapers In America The rise of newspapers in America accelerated enormously throughout the 19th century. When the century began, newspapers, generally in the larger cities and towns, tended to be affiliated with political factions or particular politicians. And while newspapers had influence, the reach of the press was fairly narrow. By the 1830s the newspaper business began to expand rapidly. Advances in printing technology meant newspapers could reach more people, and the introduction of the penny press meant that just about anyone, including newly arrived immigrants, could buy and read the news. By the 1850s the American newspaper industry came to be dominated by legendary editors, including Horace Greeley of the New York Tribune, James Gordon Bennett of the New York Herald, and Henry J. Raymond, of the upstart New York Times. Major cities, and many large towns, began to boast high-quality newspapers. By the time of the Civil War, the publics appetite for news was enormous. And newspaper publishers responded by sending war correspondents to the battlefronts. Extensive news would fill newspaper pages after major battles, and many worried families came to rely on newspapers for casualty lists. By the end of the 19th century, after a period of slow yet steady growth, the newspaper industry was suddenly energized by the tactics of two dueling editors, Joseph Pulitzer and William Randolph Hearst. The two men, engaging in what became known as Yellow Journalism, fought a circulation war that made newspapers a vital part of everyday American life. As the 20th century dawned, newspapers were read in nearly all American homes, and, without the competition from radio and television, enjoyed a period of great business success. The Partisan Era, 1790s-1830s In the early years of the United States, newspapers tended to have small circulation for several reasons. Printing was slow and tedious, so for technical reasons no one publisher could generate enormous numbers of issues. The price of newspapers tended to exclude many common people. And while Americans tended to be literate, there simply werent the large number of readers that would come later in the century. Despite all that, newspapers were felt to have profound influence on the early years of the federal government. The main reason was that newspapers were often the organs of political factions, with articles and essays essentially making the cases for political action. Some politicians were known to be connected with specific newspapers. For instance, Alexander Hamilton was a founder of the New York Post (which still exists today, after changing ownership and direction many times during more than two centuries). In 1783, eight years before Hamilton founded the Post, Noah Webster, who would later publish the first American dictionary, began publishing the first daily newspaper in New York City, the American Minerva. Websters newspaper was essentially an organ of the Federalist Party. The Minerva only operated for a few years, but it was influential and inspired other newspapers that followed. Up through the 1820s the publication of newspapers generally had some political affiliation. The newspaper was the way politicians communicated with constituents and voters. And while the newspapers carried accounts of newsworthy events, the pages were often filled with letters expressing opinions. Its worth noting that newspapers circulated widely across early America, and it was common for publishers to reprint stories which had been published in distant cities and towns. It was also common for newspapers to publish letters from travelers who had just arrived from Europe and who could relate the foreign news. The highly partisan era of newspapers continued well into the 1820s, when campaigns waged by candidates John Quincy Adams, Henry Clay, and Andrew Jackson played out on the pages of newspapers. Vicious attacks, such as in the controversial elections of 1824 and 1828, were carried in newspapers which were essentially controlled by candidates. The Rise of City Newspapers, 1830s-1850s In the 1830s newspapers transformed into publications devoted more to news of current events than outright partisanship. As printing technology allowed faster printing, newspapers could expand beyond the traditional four-page folio. And to fill the newer eight-page newspapers, content expanded beyond letters from travelers and political essays to more reporting (and the hiring of writers whose job was to go about the city and report on the news). A major innovation of the 1830s was simply lowering the price of a newspaper: when most daily newspapers cost a few cents, working people and especially new immigrants tended not to buy them. But an enterprising New York City printer, Benjamin Day, began publishing a newspaper, The Sun, for a penny. Suddenly anyone could afford a newspaper, and reading the paper every morning became a routine in many parts of America. And the newspaper industry got a huge boost from technology when the telegraph began to be used in the mid-1840s. Era of Great Editors, the 1850s Two major editors, Horace Greeley of the New York Tribune, and James Gordon Bennett of the New York Herald, began competing in the 1830s. Both editors were known for strong personalities and controversial opinions, and their newspapers reflected that. At the same time, William Cullen Bryant, who first came to public attention as a poet, was editing the New York Evening Post. In 1851, an editor who had worked for Greeley, Henry J. Raymond, began publishing the New York Times, which was seen as an upstart without any strong political direction.   The 1850s was a critical decade in American history. The split over slavery was about to tear the country apart. And the Whig Party, which had been the breeding ground of editors such as Greeley and Raymond, disintegrated over the slavery issue. The great national debates were, of course, followed close, and also influenced, by powerful editors such as Bennett and Greeley. A rising politician, Abraham Lincoln, recognized the value of newspapers. When he came to New York City to deliver his address at Cooper Union in early 1860, he knew the speech could put him on the road to the White House. And he made sure that his words got into the newspapers, even reportedly visiting the office of the New York Tribune after delivering his speech. The Civil War When the Civil War erupted the newspapers, especially in the North, responded quickly. Writers were hired to follow the Union troops, following a precedent set in the Crimean War by a British citizen considered the first war correspondent, William Howard Russell. The pages of newspapers soon filled up with news from Washington as the government prepared for war. And during the Battle of Bull Run, in the summer of 1861, a number of correspondents accompanied the Union Army. When the battle turned against the federal forces, the newspapermen were among those who hurried back to Washington in a chaotic retreat. As the war continued, the coverage of news became professionalized. Correspondents followed the armies and wrote very detailed accounts of battles which were widely read. For instance, following the Battle of Antietam, the pages of Northern newspapers carried lengthy accounts which often contained vivid details of the fighting. A staple of Civil War era newspapers, and perhaps the most vital public service, was the publication of casualty lists. After every major action newspapers would publish many columns listing the soldiers who had been killed or wounded. In one famous instance, the poet Walt Whitman saw his brothers name on a casualty list published in a New York newspapers following the Battle of Fredericksburg. Whitman hurried to Virginia to find his brother, who turned out to be only slightly wounded. The experience of being in the army camps led Whitman to become a volunteer nurse in Washington, D.C., and to write occasional newspaper dispatches on war news. The Calm Following the Civil War The decades following the Civil War were relatively calm for the newspaper business. The great editors of earlier eras, Greeley, Bennett, Bryant, and Raymond passed away. The new crop of editors tended to be very professional, but they did not generate the fireworks that earlier newspaper reader had come to expect. Technological changes, especially the Linotype machine, meant that newspapers could publish larger editions with more pages. The popularity of athletics in the late 1800s meant newspapers began having pages devoted to sports coverage. And the laying of undersea telegraph cables meant that news from very distant places could be seen by newspaper readers with shocking speed. For instance, when the distant volcanic island of Krakatoa exploded in 1883, news traveled by undersea cable to the Asian mainland, then to Europe, and then via transatlantic cable to New York City. Readers of New Yorks newspapers were seeing reports of the massive disaster with a day, and even more detailed reports of the devastation appeared in the following days. The Arrival of the Linotype Ottmar Mergenthaler was the German-born inventor of the linotype, an innovative printing system that revolutionized the newspaper industry in the late 19th century. Before Mergenthalers invention, printers had to set type one character at a time in a laborious and time-consuming process. The linotype, so called because it set a line of type at once, greatly sped up the printing process. Though Mergenthalers mechanical genius greatly changed 19th century newspapers, he had a number of problems in business. Within a few years of linotype machines becoming standard equipment at major American newspapers, Mergenthaler resigned from the company that made them. Though he was ultimately embittered, there is no doubt that his innovative technology changed the news business. Before the linotype, daily newspapers were restricted in how many changes they could make if they published more than one edition in a day. And simply because of the labor intensive nature of setting type, daily newspapers seldom extended beyond eight pages. Mergenthalers machine made multiple editions easier to routinely produce editions of 12 or 16 pages. With extra space available in daily editions, innovative publishers could pack their papers with large amounts of news which previously may have gone unreported. The Great Circulation Wars In the late 1880s the newspaper business received a jolt when Joseph Pulitzer, who had been publishing a successful newspaper in St. Louis, bought a paper in New York City. Pulitzer suddenly transformed the news business by focusing on news that he thought would appeal to common people. Crime stories and other sensational subjects were the focus of his New York World. And vivid headlines, written by a staff of specialized editors, pulled in readers. Pulitzers newspaper was a great success in New York. And in the mid-1890s he suddenly got a competitor when William Randolph Hearst, who had spent money from his familys mining fortune on a San Francisco newspaper a few years earlier, moved to New York City and bought the New York Journal. A spectacular circulation war broke out between Pulitzer and Hearst. There had been competitive publishers before, of course, but nothing like this. The sensationalism of the competition became known as Yellow Journalism. The high point of Yellow Journalism became the headlines and exaggerated stories which encouraged the American public to support the Spanish-American War. At Centurys End As the 19th century ended, the newspaper business had grown enormously since the days when one-man newspapers printed hundreds, or at most thousands, of issues. Americans became a nation addicted to newspapers, and in the era before broadcast journalism, newspapers were a considerable force in public life.