"Sublimation and Sublimation" PPT Courseware on Changes in State of Matter 8

Description

"Sublimation and Sublimation" PPT Courseware on Changes in State of Matter 8

Observe and think:

①Put a small amount of iodine (purple solid) in the test tube and heat it on an alcohol lamp, and observe purple smoke (　)

A. Still solid

B. Iodine melted into liquid state

C. It is gaseous iodine

②After cooling, it is observed that it changes from purple to transparent, and there is a purple solid on the tube wall ( )

A. Still gaseous iodine

B. It is formed by solidification of liquid iodine

C. It is directly transformed into gaseous iodine

Problem discussion:

1. In the early morning, Li Hua met Uncle Li next door on his way to school. Uncle Li said to Li Hua: "Xiaohua, it's frosty today. Did you wear more clothes? As the saying goes, 'It's cold before the frost.' It's cold after snow." Do you think Uncle Li's statement is scientific?

Frost is formed when the water vapor in the air in early winter condenses into small ice crystals and adheres to the ground when encountering strong cold at night. The temperature at night needs to drop below 0℃ for the water vapor to condense into small ice crystals, so it feels very cold. After snow, you feel cold because the snow absorbs heat when it sublimates, causing the temperature of the surrounding environment to drop.

2. In the summer of 1958, Chinese meteorologists successfully conducted artificial rainfall experiments using dry ice (solid carbon dioxide) in Northeast China for the first time, which alleviated the local drought and made the ideal of artificial "ploughing clouds and sowing rain" a reality. Please check it out Information explaining the physics of artificial rainfall methods?

Expansion and application

1. The phenomenon of matter changing directly from _____ state to _____ state is called sublimation, and the phenomenon of matter changing directly from _____ state to _____ state is called sublimation. _____ heat is required during sublimation, and _____ heat is required during sublimation.

2. Put a small amount of iodine in the flask and heat the bottom of the flask slightly. You can see that the solid iodine turns into _____. This is a _____ phenomenon. After stopping heating, you can see _____ state of iodine on the wall of the flask. , this is _____ phenomenon.

3. On cold winter mornings, outdoor objects are often covered with a layer of frost, which is ice crystals formed directly from the air.

4. Li Bai, the great poet of the Tang Dynasty, said in his poem, "I want to cross the Yellow River and the river is blocked by ice, but I am about to climb the Taihang Mountains covered with snow." The "ice" in the poem is formed by water _____, and the "snow" is formed by water vapor _____.

Reason:

After studying this class, tell me what you gained?

Exchange and cooperation

water cycle in nature

When the water vapor is cooled, part of it liquefies into small water droplets, and part of it condenses into small ice crystals.

When there are too many water droplets in the cloud, it will rain!

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For more information about the PPT courseware "Sublimation and Sublimation Changes in the State of Matter", please click the Sublimation and Sublimation ppt Changes in the State of Matter ppt tag.

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"Sublimation and Sublimation" Material Forms and Changes PPT Courseware 3 Review Review 1. What are the conversion processes between solid and liquid called? Endothermic or exothermic? The change of matter from solid to liquid is called melting, which is an endothermic process. ; The change of substance from liquid to solid is called solidification..

"Sublimation and Sublimation" Material Form and Its Changes PPT Courseware 2:

"Sublimation and Sublimation" Material Forms and Changes PPT Courseware 2 Learning Objectives 1. Know what sublimation and sublimation are, and understand the phenomena of sublimation and sublimation in life 2. Know that sublimation absorbs heat and sublimation releases heat 3. I am willing to explore the phenomena of sublimation and sublimation in life and appreciate...

"Sublimation and Sublimation" Material Forms and Changes PPT Courseware:

"Sublimation and Sublimation" Material Forms and Changes PPT Courseware Teaching Objectives 1. Know what sublimation and sublimation are, and understand the phenomena of sublimation and sublimation in life. 2. Know that sublimation needs to absorb heat and sublimation needs to release heat. 3. Understand and sublimate through experiments, observation and analysis..

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Update Time: 2024-11-16

This template belongs to Physics courseware People's Education Edition Physics for Grade 8, Volume 1 industry PPT template

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