Extended Thinking
Develop a model to explain how temperature changes affect the motion of water particles in all three states.
Based on observations, explain why water droplets form on the outside of a cold glass on a hot day.
Water droplets form on the outside of a cold glass on a hot day due to a process called condensation. When warm, moist air comes into contact with the cold surface of the glass, it cools down, and the water vapor in the air loses its ability to stay in a gaseous state. This causes the water vapor to change from a gas to a liquid, forming tiny droplets on the glass's surface.
How does increasing temperature affect the movement of water molecules?
causes water molecules to move faster and more randomly.
Does the chemical composition of water change when it changes state?
No, the chemical composition of water does not change when it changes state.
what is an chemical reaction?
rusting of iron, burning of wood, digestion of food, cooking an egg, and mixing baking soda.
Design and carry out an investigation to determine how different surfaces affect the rate of evaporation.
How would you design an experiment to show how temperature affects the rate of evaporation?
To demonstrate how temperature affects evaporation, you could design an experiment using different temperature conditions and observe the rate of water evaporation in each condition. A simple setup would involve placing identical containers of water at different temperatures (e.g., room temperature, warm water, and a cold environment like a refrigerator) and measuring the decrease in water level over time.
How does decreasing temperature cause water to change from a liquid to a solid?
its molecules slow down, losing their kinetic energy and allowing their attractions to arrange them into a fixed, crystalline structure.
What are the three states of water?
solid (ice), liquid (water), and gas (water vapor or steam).
How do you reverse an chemical reaction?
You can't reverse an chemical reaction
How could climate conditions impact the physical state of water in different environments?
altering temperatures, precipitation patterns, and ice/snow cover.
Predict what would happen if you placed an open cup of water in the freezer versus an open cup of water in a warm room.
In the freezer, the water would eventually freeze into ice. In a warm room, the water would remain in a liquid state and might eventually evaporate, depending on the room's temperature and humidity.
Compare and contrast evaporation and condensation.
Evaporation is the change of a liquid to a gas, requiring heat energy, while condensation is the change of a gas to a liquid, releasing heat energy.
What happens to water when it is heated?
its molecules gain kinetic energy, causing them to move faster and spread further apart.
How can you reverse an physical change?
Physical changes can often be reversed because they don't alter the substance's chemical identity. For example, melting ice can be reversed by refreezing the water. Similarly, dissolving salt in water can be reversed by evaporating the water, leaving the salt behind.
Synthesize information from multiple sources to construct an argument about how water cycles through different states in nature due to temperature changes.
The water cycle, driven by temperature changes, continuously moves water through solid, liquid, and gaseous states, affecting climate and ecosystems.
How can you use particle motion to explain why ice melts faster on a warm surface?
Ice melts faster on a warm surface because heat transfers more quickly from the warmer surface to the ice, increasing the kinetic energy of the water molecules and causing them to break free from their solid structure. This process speeds up the transition from solid ice to liquid water.
What role does energy play in the changing states of water?
Adding energy, like heat, can cause water to melt (solid to liquid) or evaporate (liquid to gas), increasing the kinetic energy of water molecules.
What happens to water when it is cooled below 0°C?
it typically transforms into ice, a solid form of water it typically transforms into ice, a solid form of water.
what is a physical change give an example?
A physical change is a change in the form or appearance of a substance without changing its chemical composition.
How could understanding the physical changes of water help engineers design better systems for water conservation?
Allowing them to predict water movement, optimize resource management, and minimize losses.
Using evidence, argue why melting and freezing are examples of physical changes rather than chemical changes.
Melting and freezing are physical changes, not chemical changes, because they involve a change in state (solid, liquid, or gas) without altering the chemical composition of the substance. Specifically, in both processes, the substance remains the same chemical compound, H2O (water), just in a different physical form.
How can you demonstrate a physical change in water using common household items?
A simple way to demonstrate a physical change in water is by melting ice, which is a solid, into liquid water. This change is reversible, meaning you can freeze the water back into ice. Boiling water to create steam is another example, and the steam can condense back into liquid water.
What is the term for when a gas turns back into a liquid?
The process of a gas turning back into a liquid is called condensation. This occurs when a gas loses energy, typically by cooling, and its molecules come closer together, forming a liquid.
Develop a step-by-step procedure for separating a mixture containing sand, salt, and iron filings. Justify why you chose each separation method and how it demonstrates physical changes.
Step 1: Use a magnet to remove the iron filings (magnetism).
Step 2: Add water to the sand and salt mixture. The salt will dissolve while the sand remains.
Step 3: Use filtration to separate the sand from the saltwater solution.
Step 4: Evaporate the water to retrieve the salt.