If you build a campfire, you start with a large stack of sticks and logs. As the fire burns, the stack slowly shrinks. By the end of the evening, all that is left is a small pile of ashes. What happened to the matter that you started with? Was it destroyed by the flames? It may seem that way. What do you think happened? The truth is that the same amount of matter still exists. The wood changed not only to ashes, but also to carbon dioxide, water vapor, and other gases. The gases floated off into the air, leaving behind just the ashes. Although matter was changed, it was not created or destroyed. Because the same amount of matter still exists, we can say that matter is conserved. You may wonder how it can be conserved if something is now missing? Assume you had measured the mass of the wood before you burned it. Assume you had also trapped the gases released by the burning wood and measured their mass and the mass of the ashes. What would you find? The ashes and gases combined have the same mass as the wood you started with. This example illustrates the law of conservation of mass.

What can cause wood to change to ashes, carbon dioxide, water vapor, and other gases?

Milwaukee, Wisconsin (CNN) -- President Barack Obama, in a bid to create jobs and boost economic growth, called on Congress on Monday to pass a $50 billion plan to renew the country's transportation infrastructure. His address was the first of two speeches the president is scheduled to make this week to frame his administration's ongoing response to the recession, less than two months ahead of midterm elections in which Democratic majorities in the House and Senate are in jeopardy. "Today, I am announcing a new plan for rebuilding and modernizing America's roads, and rails and runways for the long term," said Obama, who spoke on Labor Day in Milwaukee, Wisconsin -- a state with competitive gubernatorial and U.S. Senate races. "We used to have the best infrastructure in the world. We can have it again," he said to loud cheers from a crowd of union workers. The proposal envisions -- over a six year period -- rebuilding 150,000 miles of roads, 4,000 miles of rail and 150 miles of airport runways. It also would include modernizing the nation's air traffic control system in an effort to reduce delays and travel time. "This will not only create jobs immediately. It's also going to make our economy hum over the long haul," said the president. Obama hopes to work with Congress to enact an up-front investment of $50 billion -- an amount a White House statement said would represent a significant chunk of new spending on infrastructure. The investment would then be paired with what the administration called a framework to improve transportation spending. The long-term plan would include the establishment of an Infrastructure Bank, which would leverage federal dollars and focus on projects that could deliver the the biggest bang for the buck, Obama said. The president stressed the need for Democrats and Republicans to work together on the transportation initiative, which would need to be approved by Congress.

The plan for rebuilding and modernizing America's roads, and rails and runways for the long term would have what immediate effect?

Boone, Ia. -Poor and elderly people may soon go without legal representation in Boone County. Boone County Legal Aid, which for 31 years has provided legal services to those who couldn't afford them, will close in February if a $10,000 grant from Prairie Meadows Racetrack and Casino is not awarded. The legal service is one of the few programs in Iowa that offers legal representation to those who qualify without turning to the state for its services. "It is a very sad situation, but that's the fact," said Alan Schroeder, city attorney and supervisor of Boone County Legal Aid. For the past two years using money mostly from the city and county, Schroeder has upheld the outfit alone, taking on about 60 clients a year, and settling cases that range from domestic abuse to bankruptcy. He also has a private practice. If the legal service closes, he's unsure where his clients will go. The city of Boone gave Schroeder $6,300 in July to resolve pending cases, said Kathy Berg, Boone's finance officer. Without that, the program might already be closed. "All governments are having problems with finances," Boone Mayor George Maybee said. "No one else stepped in. The county didn't. The state didn't." Donovan Olson, chairman of the county Board of Supervisors, said the board quit funding the legal service in July because it felt the county didn't need it. Drake University ended its funding after the 2000 spring semester "for a variety of reasons," Suzanne Levitt, the law professor who oversaw the program, said via e-mail. Olson said Schroeder must prove Prairie Meadows is the primary money source for the board to grant the program any more money. Schroeder ran the program without the help of law students or Drake, which had provided as much as two-thirds of the money in some years.
Who has not stepped in to help Boone County Legal Aid?