Problem: If a solution has a higher concentration of hydronium ions than pure water, it has a pH lower than 7. A solution with a pH lower than 7 is called an acid . As the hydronium ion concentration increases, the pH value decreases. Therefore, the more acidic a solution is, the lower its pH value is. Did you ever taste vinegar? Like other acids, it tastes sour. Stronger acids can be harmful to organisms. For example, stomach acid would eat through the stomach if it were not lined with a layer of mucus. Strong acids can also damage materials, even hard materials such as glass. In his chemistry lab David is learning about acids. He took three solutions to identify them correctly, sample A, sample B, and sample C. Sample A is a strong acid; sample B is a weak acid; and sample C is not an acid. David needs to identify the content of each sample by learning about their attributes. Which sample would most likely damage materials, sample A or sample B?

A: sample A

Problem: Given the question: In grassland, much of the organic matter added to the soil is from the deep, fibrous, grass root systems. By contrast, tree leaves falling on the forest floor are the principal source of soil organic matter in the forest. Another difference is the frequent occurrence in the grasslands of fires that destroy large amounts of aboveground material but stimulate even greater contributions from roots. Also, the much greater acidity under any forests inhibits the action of certain soil organisms that otherwise would mix much of the surface litter into the mineral soil. As a result, the soils under grasslands generally develop a thicker A horizon with a deeper distribution of organic matter than in comparable soils under forests, which characteristically store most of their organic matter in the forest floor (O horizon) and thin A horizon. Kim and Jane inherited some land. Kim inherited some grassland, while Jane inherited a forest. They both took good care of their properties. Which person inherited a parcel where leaves are not the principal source of soil organic matter?
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The answer is:
Kim

input question: In nature, when the population size is small, there is usually plenty of food and other resources for each individual. When there is plenty of food and other resources, organisms can easily reproduce, so the birth rate is high. As the population increases, the food supply, or the supply of another necessary resource, may decrease. When necessary resources, such as food, decrease, some individuals will die. Overall, the population cannot reproduce at the same rate, so the birth rates drop. This will cause the population growth rate to decrease. Two neighboring islands had different sized populations. Green island had a small population. Red island had a large population and environmental problems. Researchers studied these islands over a span of 5 decades. Which island had plenty of food for its inhabitants????
output answer: Green

Clouds on Earth are made of water vapor. Venus's clouds are a lot less pleasant. They are made of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid! The atmosphere of Venus is so thick that the pressure on the surface of Venus is very high. In fact, it is 90 times greater than the pressure at Earth's surface! The thick atmosphere causes a strong greenhouse effect. As a result, Venus is the hottest planet. Even though it is farther from the Sun, Venus is much hotter even than Mercury. Temperatures at the surface reach 465C (860F). That's hot enough to melt lead! Two students were learning about atmospheres and planets. Dan learned about the atmosphere of Earth, while Nate learned about planet Venus and its atmosphere. Which student learned less about the planet with a strong greenhouse effect?
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Answer: Dan

Q: Plants called epiphytes grow on other plants. They obtain moisture from the air and make food by photosynthesis. Most epiphytes are ferns or orchids that live in tropical or temperate rainforests (see Figure below ). Host trees provide support, allowing epiphyte plants to obtain air and sunlight high above the forest floor. Being elevated above the ground lets epiphytes get out of the shadows on the forest floor so they can get enough sunlight for photosynthesis. Being elevated may also reduce the risk of being eaten by herbivores and increase the chance of pollination by wind. Hawk and Brunt were two colleagues studying about plants. Later on, Hawk got specialized in normal plants, while Brunt decided to learn more about epiphytes. Which colleague studied less about orchids?
A: Hawk

[Q]: Continued heating of the water after the ice has completely melted will now increase the kinetic energy of the liquid molecules and the temperature will rise. Assuming that the atmospheric pressure is standard, the temperature will rise steadily until it reaches 100C. At this point, the added energy from the heat will cause the liquid to begin to vaporize. As with the previous state change, the temperature will remain at 100C while the water molecules are going from the liquid to the gas or vapor state. Once all the liquid has completely boiled away, continued heating of the steam (remember the container is closed) will increase its temperature above 100C. Tommy sets two pots of water on the stove and sets each burner to a different temperature. Pot F is set on a burner with a temperature below the boiling point and Pot G is on a burner set to above the boiling point. Tommy walks away to check his email and comes back fifteen minutes later to check on his water. The water in which pot will begin to vaporize?
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[A]:
Pot G