1.
Which of the following could solid ice become if heat energy is added? (Check all that apply)
Correct Answer(s)
B. Liquid Water
C. Vapor
Explanation
When heat energy is added to solid ice, it undergoes a phase change and can become either liquid water or vapor. The added heat energy causes the ice particles to gain enough energy to break their bonds and transition into a liquid state, forming liquid water. If more heat energy is added, the liquid water molecules gain even more energy and can transform into a gaseous state, forming vapor. Therefore, both liquid water and vapor are possible outcomes when heat energy is added to solid ice.
2.
If isopropyl alcohol is a liquid at room temperature (25 degrees Celsius), which of the following must its boiling point be?
Correct Answer
D. 82 Degrees Celsius
Explanation
Isopropyl alcohol is a liquid at room temperature, which means its boiling point must be higher than 25 degrees Celsius. Among the given options, the only temperature higher than 25 degrees Celsius is 82 degrees Celsius. Therefore, 82 degrees Celsius must be the boiling point of isopropyl alcohol.
3.
Which of the following terms identifies the change from a liquid to solid?
Correct Answer
B. Solidification
Explanation
Solidification is the term that identifies the change from a liquid to a solid. This process occurs when the temperature of a substance decreases below its freezing point, causing the particles to slow down and arrange themselves into a fixed, orderly structure. This transformation involves the release of heat energy and results in the formation of a solid with a definite shape and volume.
4.
Oxygen becomes a gas at -183 degrees Celsius. We would call this temperature?
Correct Answer
A. Boiling point
Explanation
The boiling point is the temperature at which a substance changes from a liquid to a gas. In this case, oxygen becomes a gas at -183 degrees Celsius, so we would call this temperature the boiling point.
5.
The following occurs when heat energy is removed:Gas ---(A)--> Liquid ---(B)---> SolidWhat would be the phase changes for A and B respectfully?
Correct Answer
C. Condensation, Freezing
Explanation
When heat energy is removed, the gas phase changes to a liquid phase, which is condensation (A). Then, the liquid phase changes to a solid phase, which is freezing (B).
6.
Examine the following sequence of phase changes:Solid ---> Liquid ---> GasWould we need to ADD or REMOVE heat energy?
Correct Answer
A. Add heat energy
Explanation
In this sequence of phase changes, the substance is transitioning from a solid to a liquid and then to a gas. These phase changes require the addition of heat energy. When a solid is heated, it gains energy and melts into a liquid. Similarly, when a liquid is heated, it gains energy and vaporizes into a gas. Therefore, in order to facilitate these phase changes, heat energy needs to be added to the substance.
7.
Freezing is to solid, as sublimation is to ______________________
Correct Answer
C. Gas
Explanation
Freezing is the process of a substance changing from a liquid to a solid state. Similarly, sublimation is the process of a substance changing directly from a solid to a gas state, bypassing the liquid state. Therefore, the correct answer is "Gas".
8.
If chemical "X" had the following physical properties:Melting Point = - 32 Degrees CelsiusBoiling Point = -11 Degrees Celsiuswhat state of matter would you find Chemical "X" if the temperature was 0 Degrees Celsius?
Correct Answer
C. Gas
Explanation
If the temperature of chemical "X" is 0 degrees Celsius, which is higher than its boiling point (-11 degrees Celsius) and melting point (-32 degrees Celsius), it would be in a gaseous state. At this temperature, chemical "X" would have enough energy to overcome the forces holding its particles together, causing it to exist as a gas.
9.
When isopropyl alcohol was spilled over the counter top and quickly disappeared, what phase change occurred?
Correct Answer
A. Evaporation
Explanation
When isopropyl alcohol is spilled over the counter top and quickly disappears, it indicates that a phase change of evaporation has occurred. Evaporation is the process by which a liquid changes into a gas at a temperature below its boiling point. In this case, the isopropyl alcohol molecules gain enough energy from the surroundings to overcome the attractive forces between them, causing them to escape into the air as a gas. This is why the alcohol quickly disappears from the counter top.
10.
A student noticed frost was on the ground at 6:30 a.m. but noticed it disappeared by 8:30 a.m. What phase change was responsible for turning the frost into water vapor?
Correct Answer
C. Sublimation
Explanation
The phase change responsible for turning the frost into water vapor is sublimation. Sublimation is the process in which a solid directly changes into a gas without going through the liquid phase. In this case, the frost on the ground skipped the melting phase and directly transformed into water vapor due to the low temperature and pressure conditions.