"Sublimation and Sublimation" PPT Courseware on Changes in State of Matter 3

Description

"Sublimation and Sublimation" PPT Courseware on Changes in State of Matter 3

Exploration experiment

sublimation of iodine

1. During the experiment, when the iodine in the flask was heated, what phenomena were seen in the cup? Is there any liquid iodine present?

2. Why do you need to use an alcohol lamp for heating? Is it okay without heating?

3. Stop heating. What phenomenon do you see?

4. What conclusions can you draw from the experiment?

sublimation

The phenomenon of matter changing directly from solid to gaseous state

Sublimation requires heat absorption

Sublime

The phenomenon of matter changing directly from gaseous state to solid state

Sublimation requires heat release

The dry ice sprayed on the stage instantly sublimates, absorbing heat from the surroundings, causing the temperature to drop. When the surrounding water vapor is cooled, it liquefies into small water droplets or condenses into small ice crystals suspended in the air, which is the smoke we see.

(Water vapor close to the dry ice will directly condense into small ice crystals)

You must have seen the CCTV gala. Spraying dry ice on the stage can produce wisps of blue clouds or light mist. How is this special effect produced?

Other applications of dry ice:

Widely used in stage, theater, film and television, wedding, celebration, party effects, etc.

When fresh fish is transported by train, it guards next to the fresh fish and plays the role of refrigeration and preservation. Dry ice looks like ice and can be used as a preservative. It is much better than ice. When dry ice melts, it does not turn into liquid like ice. It completely sublimates and the surrounding area is clean. The cooling temperature of dry ice is much lower than that of ice, and the carbon dioxide gas produced after dry ice sublimates can inhibit the reproduction and growth of bacteria.

practise

1. Among the following descriptions about the formation of clouds, dew, fog, and frost, which one is correct ( )

A. Clouds are formed when water vapor rises to high altitudes, the temperature drops and condenses into small water droplets and sublimates into small ice crystals.

B. Fog is formed by the liquefaction of air floating on floating dust.

C. Dew is small ice crystals in clouds that melt into small water droplets

D. Frost is when water vapor in the air first liquefies into small water droplets and then solidifies into small ice crystals

2. On winter mornings, ice flowers often appear on the windows of occupied rooms. The following statement is correct: ( )

A. Appears on the inside of the window and is formed by the condensation of a large amount of water vapor.

B. Appears on the inside of the window and is made of water.

C. Appears on the outside of the window and is formed by the condensation of a large amount of water vapor.

D. Appears on the outside of the window, made of water condensation

3. Mao Zedong, a great man of the generation, wrote in "Qinyuan Spring Snow" that "the scenery of the North is covered with ice for thousands of miles and snow drifting for thousands of miles." The main physical changes that form this natural scene are ( )

A. Melting and vaporization b. solidification and liquefaction

C. .Condensation and sublimation D． Vaporization and sublimation

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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.

"Sublimation and Sublimation" Material Forms and Changes PPT Courseware 3:

"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: 2024-09-09

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

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