Rob was in his chemistry lab, experimenting with different states of matter. He had a liquid substance that he labeled as state A. He then transformed half of the liquid substance to gaseous state. He labeled it as state B. Finally, he froze the remaining half of the liquid to solid state. He labeled it as state C. Which does not represent a decrease in etropy, state A or state C? Hint: There are many examples in the chemical world of changes in entropy. Phase transitions are one obvious example. When a substance makes a transition from the liquid state to the gaseous state, the particles have many more possible arrangements, because they are no longer confined to a specified volume in which they are close to each other; gas particles can move freely throughout their container. Vaporization represents an increase in entropy. In the opposite direction, a liquid loses entropy when it freezes to a solid. Because solids have very ordered structures, there are fewer possible arrangements of particles that would result in the properties associated with a solid.
Ans: state A

Dan is conducting a research to see how a substance behaves in varying pressure. First, he selects a gaseous substance in very low pressure. He calls it as case A. Then he increases the pressure. He calls it case B. Finally, he increases the pressure even further. He calls it case C. Which case would see more distance between particles, case B or case C? Hint: Start right above point on the temperature axis and follow the red line vertically. At very low pressure, the particles of the substance are far apart from one another and the substance is in the gas state. As the pressure is increased, the particles of the substance are forced closer and closer together. Eventually the particles are pushed so close together that attractive forces cause the substance to condense into the liquid state. Continually increasing the pressure on the liquid will eventually cause the substance to solidify. For the majority of substances, the solid state is denser than the liquid state and so putting a liquid under great pressure will cause it to turn into a solid. The line segment represents the process of sublimation, where the substance changes directly from a solid to a gas. At a sufficiently low pressure, the liquid phase does not exist. The point labeled is called the triple point . The triple point is the one condition of temperature and pressure where the solid, liquid, and vapor states of a substance can all coexist at equilibrium.
Ans: case B

Two scientists went to Antarctica for research. Tim was assigned to East Antarctica, while John was assigned to West Antarctica. They spent 6 months there. Which scientist was located at a higher elevation? Hint: East Antarctica is colder than its western counterpart because of its higher elevation. Weather fronts rarely penetrate far into the continent, leaving the centre cold and dry. Despite the lack of precipitation over the central portion of the continent, ice there lasts for extended periods. Heavy snowfalls are common on the coastal portion of the continent, where snowfalls of up to 1.22 metres (48 in) in 48 hours have been recorded.
Ans: Tim

People in the coastal area naturally get more iodide from food items because the soil has more iodized salt. But farther we go inland, the soil lacks necessary iodine. As a result, inland population do not get enough iodine naturally. Where people are in acute need of added iodide, coastal area or inland? Hint: Before iodized salt was developed, some people experienced a number of developmental difficulties, including problems with thyroid gland function and mental retardation. In the 1920s, we learned that these conditions could usually be treated easily with the addition of iodide anion to the diet. One easy way to increase iodide intake was to add the anion to table salt. This simple step greatly enhanced health and development. Large amounts of iodide ion are also found in seaweed such as kelp (see picture above) and saltwater fish.
Ans: inland