Physics 6 Lesson 27: Evaporation and Condensation (continued)
1. Summary of theory Tóm
1.1. What is condensation?
Condensation is the change from a vapor to a liquid.
- When standing in front of the mirror and blowing a long breath into the mirror, we see an opaque patch on the mirror. The opacity is the water vapor in our breath that condenses into tiny droplets of water on the mirror surface.
- Put an ice cube in a glass of water, after a while, there are drops of water on the outside of the cup. That’s because water vapor in the air condenses.
1.2. Characteristics of condensation
Condensation is the reverse process of evaporation, the higher the temperature, the faster the evaporation rate, the lower the temperature, the faster the condensation occurs.
1.3. Draw conclusions
C1: What is the difference between the temperature of the water in the control cup and in the test cup?
C2: What happens on the outside of the test cup? Does this phenomenon occur with the control cup?
C3: Are the water droplets standing on the outside of the test cup being in the seepage cup?
No, because the water standing on the outside of the cup is colorless, it cannot penetrate the glass.
C4: Where do the drops of water outside the test cup come from?
C5: So is our prediction correct?
2. Illustrated exercise
Question 1: Explain the formation of water droplets on leaves at night?
At night, the temperature drops, the water vapor in the night air gets cold, condensing into dew drops on the leaves.
Verse 2: Why does wine stored in an uncorked bottle will dry up, but if it is closed, it won’t run out?
When the lid is not closed, the open surface of the wine is open to the outside air, so the evaporation occurs stronger than the condensation, so the alcohol vapor escapes into the air, so the alcohol gradually dries up.
Wine in a bottle also has two processes of evaporation and condensation, but as much alcohol in a sealed bottle as evaporates, there is also a condensation so the amount of alcohol will not decrease.
3.1. Essay exercises
Question 1: When cooking rice, we open the lid and see that there are drops of water inside the lid, what is the cause?
Verse 2: What are clouds made of?
Question 3: Why do we often see a very thin layer of water on it when holding a mini gas cylinder in use?
Verse 4: When it’s cold, the car has the air conditioner on and the doors are closed, what phenomenon do passengers in the car see?
3.2. Multiple choice exercises tập
Question 1: Condensation is the transition from
A. solid to liquid
B. liquid to solid
C. vapor to liquid
D. liquid to vapor
Verse 2: There is water on the outside of the ice cup because:
A. The water in the cup can seep out.
B. Water vapor in the air condenses and cools to form water.
C. The water in the cup evaporates to the outside.
D. Water in the air condenses on the side of the cup.
Question 3: Which of the following is related to condensation?
A. Smoke coming from the kettle faucet vòi
B. The water in the cup dries up
C. Hanging clothes to dry
D. Formation of water
Verse 4: Which of the following is not condensation?
A. Water vapor in the clouds after a while will form rain.
B. When breathing into the window glass, small water droplets will appear to blur the glass.
C. The formation of water droplets on leaves at night.
D. The rainwater on the asphalt road disappears when the Sun reappears after the rain.
Through this lesson, students will be familiar with the knowledge related to Evaporation and Condensation (continued) along with related exercises at various levels from easy to difficult, etc. Okay:
Understand the concept of condensation.
State the characteristics of condensation.
Relationship between evaporation and condensation.