"Salt and Cement" PPT courseware

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"Salt and Cement" PPT courseware

Part One: Changes in Salt

Light the alcohol lamp and heat the salt water. Observe what happens to the salt water?

You can clearly see the precipitated salt particles. (restored to its original state)

Experimental results

Dissolved salt can be restored to its original state by heating salt water.

Salt and cement PPT, part 2: changes in cement

Guess what will happen to the cement if you add water to it?

It will not dissolve and will solidify after a while.

What happens to cement when it is heated? Will it be restored to its original state?

The cement will never return to its original shape.

There are many kinds of changes in matter, which can be divided into reversible changes and irreversible changes according to whether they can be restored to their original state.

Reversible change: After changes occur in substances such as salt, water, and glass, they can be restored to their original state through a certain method. This change is called reversible change.

Irreversible change: Materials such as cement, wood, seeds, etc. cannot be restored to their original state after being changed. This kind of change is called irreversible change.

Salt and Cement PPT, Part 3 Content: Standard Practice:

1. Once cement is mixed with water, it cannot return to its original state. This change is called __________ change.

2. Water can turn into ice under certain temperature conditions, or ice can turn into water. This change is called _____ change.

3. The change between the iron block and the molten iron is ( ) change

A． Reversible B. irreversible

4. The thermal expansion and contraction of an object is a ( ) change

A． Reversible B. irreversible

5. There is a ( ) change between beans and tofu

A． Reversible B. Irreversible

6. The river flowing eastward is a ( ) change

A． Reversible B. irreversible

Keywords: Qingdao version fifth grade science PPT courseware free download, salt and cement PPT download, .PPT format;

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"Salt and Cement" PPT:

"Salt and Cement" PPT Part One Content: Characteristics of Salt and Cement Add salt to water and observe the changes of salt. How to make salt in water reappear? Observing the changes in cement... Salt and cement PPT, Part 2 content: Summary Like salt...

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Update Time: 2024-10-05

This template belongs to science courseware Qingdao Edition Fifth Grade Science Volume 1 industry PPT template

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