Question: For most substances, when the temperature of the solid is raised high enough, the substance changes to a liquid, and when the temperature of the liquid is raised high enough, the substance changes to a gas. We typically visualize a solid as tiny particles in constant motion held together by attractive forces. As we add heat to the solid, the motion, or the kinetic energy, of the particles increases. At some temperature, the motion of the particles becomes great enough to overcome the attractive forces. The thermal energy that was added to the solid up to this point was absorbed by the solid as kinetic energy, increasing the speed of the molecules. The lowest temperature at which the particles are able to exist in the liquid form is called the melting point . As a science experiment for his school homework, Kendra is putting two ice cubes on separate pans and then putting those pans on burners set to different temperatures. Ice cube A is set on top of a burner set to a low temperature, and ice cube B is placed on a burner set quite a bite higher. One minute later, Kendra begins writing down what she sees happening to the ice cubes. Does ice cube B have more or less kinetic energy than ice cube A?
Answer: more

Question: Further heating then adds energy to the liquid particles, increasing their speed, kinetic energy, and temperature. This is the second slope on the curve. Once the particles are energetic enough to completely break free of each other, they start to enter the gas phase. Boiling occurs at the second plateau of this curve, and the temperature at this point is referred to as the boiling point . Again, the added heat is being used to break up the interactions between particles instead of increasing their kinetic energy, so no temperature increase is observed until all particles are in the gas phase. Finally, adding even more energy will further speed up the gas particles, increasing the kinetic energy and temperature of the substance. Will is doing some testing with heat. He freezes some water in a cup then takes the ice cube and puts it into a pot. He places a thermometer on the ice cube and takes readings. To his surprise, the temperature on the thermometer is stable the entire time it's on the ice cube, Then the ice cube completely melts. Will the temperature of pure liquid water ever go below its freezing point before freezing, yes or no?
Answer: no

Question: When a solid substance is involved in a chemical reaction, only the matter at the surface of the solid is exposed to other reactants. If a solid has more surface area, more of it is exposed and able to react. Therefore, increasing the surface area of solid reactants increases the reaction rate. Look at the hammer and nails pictured in the Figure below . Both are made of iron and will rust when the iron combines with oxygen in the air. However, the nails have a greater surface area, so they will rust faster. John is trying to figure out how the shape of an object affects how it reacts with other elements. For that, he chose two objects, both made of the same element - object A and object B. Object A has a larger surface area, but object B has smaller surface area. He let these objects to react with other reactants to see how the processes work. Which object would be more exposed to the reactants, object A or object B?
Answer:
object A