QUES: Surely, you have noticed the tall poles along the roadside. Do you know what is on top of those poles? Thats right, wires that carry electric current. These wires carry electric current to your home. But what is electric current? Electric current is actually the flow of electrons. You may recall, an electron is the outer-most particle in an atom. They have a negative charge. Electricity is the continuous flow of these particles. Electrons are able to move through wires. Their speed can even be measured. The SI unit for electric current (or speed) is the ampere (A). Ampere is often shortened to amp. Electric current may flow in just one direction, or it may keep reversing direction. Direct current (DC) flows in only one direction. Direct current is what is used in devices like flashlights. Alternating current (AC) flows in two directions. This is the type of current that flows into your home through wires.
Do you have any questions?
MY QUESTION: What is created when the outer-most particles of an atom are flowing?

QUES: Magnetism is the ability of a material to be attracted by a magnet. It also include the ability for some material to act like a magnet. No doubt youve handled refrigerator magnets. You can see some in Figure 1.28. You probably know they stick to a metal refrigerator. This is what holds your homework up. Maybe your little sisters drawings are hung on the fridge in this manner. Do magnets stick to all materials? Of course not. You have probably checked and they do not stick to other surfaces. They do not stick to wooden doors or glass windows. Wood and glass are not attracted to a magnet. Obviously, only certain materials are attracted to magnets.
Do you have any questions?
MY QUESTION: What is magnetism?

QUES: Alexis-Charles-Henri Clerel de Tocqueville (French: [aleksi SaRl aRi kleRel d@ tokvil]; 29 July 1805 - 16 April 1859) was a French political thinker and historian best known for his works Democracy in America (appearing in two volumes: 1835 and 1840) and The Old Regime and the Revolution (1856). In both of these, he analyzed the improved living standards and social conditions of individuals, as well as their relationship to the market and state in Western societies. Democracy in America was published after Tocqueville's travels in the United States, and is today considered an early work of sociology and political science. Tocqueville was active in French politics, first under the July Monarchy (1830-1848) and then during the Second Republic (1849-1851) which succeeded the February 1848 Revolution. He retired from political life after Louis Napoleon Bonaparte's 2 December 1851 coup, and thereafter began work on The Old Regime and the Revolution. He argued that the importance of the French Revolution was to continue the process of modernizing and centralizing the French state which had begun under King Louis XIV. The failure of the Revolution came from the inexperience of the deputies who were too wedded to abstract Enlightenment ideals. Tocqueville was a classical liberal who advocated parliamentary government, but was skeptical of the extremes of democracy.
Do you have any questions?
MY QUESTION: Which of Tocqueville's two best known works was published after the February 1848 Revolution?

QUES: Tuesday, September 11, 2001, dawned temperate and nearly cloudless in the eastern United States. Millions of men and women readied themselves for work. Some made their way to the Twin Towers, the signature structures of the World Trade Center complex in New York City. Others went to Arlington, Virginia, to the Pentagon. Across the Potomac River, the United States Congress was back in session. At the other end of Pennsylvania Avenue, people began to line up for a White House tour. In Sarasota, Florida, President George W. Bush went for an early morning run. For those heading to an airport, weather conditions could not have been better for a safe and pleasant journey. Among the travelers were Mohamed Atta and Abdul Aziz al Omari, who arrived at the airport in Portland, Maine. Boston: American 11 and United 175. Atta and Omari boarded a 6:00 A.M. flight from Portland to Boston's Logan International Airport. When he checked in for his flight to Boston, Atta was selected by a computerized prescreening system known as CAPPS (Computer Assisted Passenger Prescreening System), created to identify passengers who should be subject to special security measures. Under security rules in place at the time, the only consequence of Atta's selection by CAPPS was that his checked bags were held off the plane until it was confirmed that he had boarded the aircraft. This did not hinder Atta's plans. Atta and Omari arrived in Boston at 6:45. Seven minutes later, Atta apparently took a call from Marwan al Shehhi, a longtime colleague who was at another terminal at Logan Airport. They spoke for three minutes. It would be their final conversation.
Do you have any questions?
MY QUESTION:
On what day did Atta and Omari board a 6:00 A.M. flight from Portland to Boston's Logan International Airport?