Problem: 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.

Question: "What is left when the stack shrinks?"

Answer: "Small pile of ashes"

OPTIONS:
- no
- yes
Answer: yes

Problem: Physical properties include the state of matter. We know these states as solid, liquid, or gas. Properties can also include color and odor. For example, oxygen is a gas. It is a major part of the air we breathe. It is colorless and odorless. Chlorine is also a gas. In contrast to oxygen, chlorine is greenish in color. It has a strong, sharp odor. Have you ever smelled cleaning products used around your home? If so, you have probably smelled chlorine. Another place you might smell chlorine is at a public swimming pool. The chlorine is used to kill bacteria that may grow in the water. Other physical properties include hardness, freezing, and boiling points. Some substances have the ability to dissolve in other substances. Some substances cannot be dissolved. For example, salt easily dissolves in water. Oil does not dissolve in water.

Question: "What are the properties of Chlorine?"

Answer: "green color"

OPTIONS:
- no
- yes
Answer: yes

Problem: (CNN) -- Declaring 2010 "The best year in safety performance in our company's history," Transocean Ltd., owner of the Gulf of Mexico oil rig that exploded, killing 11 workers, has awarded its top executives hefty bonuses and raises, according to a recent filing with the U.S. Securities and Exchange Commission. That includes a $200,000 salary increase for Transocean president and chief executive officer Steven L. Newman, whose base salary will increase from $900,000 to $1.1 million, according to the SEC report. Newman's bonus was $374,062, the report states. Newman also has a $5.4 million long-term compensation package the company awarded him upon his appointment as CEO in March 2010, according to the SEC filing. The latest cash awards are based in part on the company's "performance under safety," the Transocean filing states. "Notwithstanding the tragic loss of life in the Gulf of Mexico, we achieved an exemplary statistical safety record as measured by our total recordable incident rate and total potential severity rate," the SEC statement reads. "As measured by these standards, we recorded the best year in safety performance in our Company's history." The company called that record "a reflection on our commitment to achieving an incident-free environment, all the time, everywhere," the SEC filing states. The company did not respond to an e-mail from CNN seeking comment. The April 20, 2010, explosion on the Deepwater Horizon rig injured 17 workers and killed 11 others, including nine Transocean employees, according to the SEC filing. It has been called the worst spill in U.S. history. The well was capped three months later, but not before millions of barrels of oil spilled into the Gulf. In January, President Barack Obama's National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling released a report that spread blame for the accident among Transocean, BP -- which leased the rig -- and Halliburton, which installed the rig's cement casing.

Question: "What is the name of the oil rig in the Gulf of Mexico"

Answer: "Deepwater Horizon"

OPTIONS:
- no
- yes
Answer:
yes