"Cement and Asphalt" Highway PPT Courseware 3

Description

"Cement and Asphalt" Highway PPT Courseware 3

What we just saw was a scene of building roads and bridges. Students, think about it, what materials are usually used to build roads and bridges?

Cement, asphalt, steel, etc.

learning target

1. I know that some changes in matter are reversible and some are irreversible. Recognize the impact of these changes on human life.

2. I know that there are two major types of changes in matter, one is just a change in form, and the other will produce new matter.

3. I can carry out scientific experimental design and careful observation in cement and asphalt change experiments.

1. Observation and Experiment

1. What are the characteristics of cement and asphalt?

The shape of cement - powder.

Cement color----grey

The shape of asphalt----block

Asphalt color----black

2. What will happen when water is added to cement and mixed?

After a while it will turn into a harder block.

3. Can the cement return to its original powder form after adding water and turning it into a block?

cannot.

We call changes like cement that create new substances and cannot return to their original appearance called irreversible changes.

For example, how do people use irreversible change processes and reversible change processes?

Using the reversible process of iron melting to produce a variety of vehicles

Exploiting the possible transformation processes of asphalt to pave roads

Using the impossible transformation process of cement to build many projects

4. What will asphalt look like after heating? What does it look like after cooling?

It will gradually become liquid after heating

After cooling, it returned to its original shape.

We call asphalt a reversible change that only changes its form and can return to its original appearance.

summary

Changes in matter are divided into two categories, one is just a change in form, such as salt and sugar dissolving in water, logs are split into firewood, ice melts into water, and wheat is ground into flour; the other is a change that produces new substances. Changes, such as: stir-frying, steaming steamed buns, burning limestone into lime, burning firewood, etc.

Keywords: highway teaching courseware, cement and asphalt teaching courseware, E-education version fifth grade science PPT courseware download, fifth grade science slide courseware download, highway PPT courseware download, cement and asphalt PPT courseware download, .PPT format;

For more information about the "Highway Cement and Asphalt" PPT courseware, please click the Highway ppt Cement and Asphalt ppt tab.

"Cement and Asphalt" Highway PPT Courseware 2:

"Cement and Asphalt" Highway PPT Courseware 2 Cement and asphalt are often used in paving roads and building bridges. What do we know about cement and asphalt? Guess what happens when you add a small amount of water to cement? Experimental tips: 1. Don’t add too much water, but do it in batches.

"Cement and Asphalt" Highway PPT Courseware:

"Cement and Asphalt" Highway PPT Courseware What do you know about cement and asphalt? Guess what happens when you add a small amount of water to cement? Changes in cement: 30 seconds after mixing, the color of the cement changes to dark gray, becomes fluid, and disperses..

File Info

Update Time: 2024-10-27

This template belongs to science courseware E-education edition fifth grade science volume 1 industry PPT template

Preview