"Make a Pebble" PPT download

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"Make a Pebble" PPT download

Part One: Examining Pebbles

When you walk on the river or beach, you can see many rocks without edges like walnuts and peas. People call these rocks pebbles.

Seeing these colorful pebbles, they are crystal clear, rich in color, and smooth in surface... You can use many idioms to praise them. These are not enough, but it fascinates me because of its charm. I am fascinated by it because its beauty deeply touches me. It is enough to show off its beauty in the world, but it is a pity that no one competes with it for its beauty. It is the beauty among stones.

Seeing these pebbles, one can’t help but wonder, why are the pebbles so smooth? How are pebbles formed? Please go to the river or beach to investigate, or do the experiment yourself, and you will understand.

Part 2: The formation of pebbles

Pebbles are formed due to weathering, which is the destruction of rocks. In science class, we know that objects have the property of thermal expansion and contraction, and the same is true for rocks. Due to the large temperature difference between day and night, and the large changes in cold and heat throughout the year, they will become soft and cracked over time.

Destroy rocks

Plants have strong vitality. The roots of a seedling are thin and short. They penetrate into the cracks of rocks and absorb water and nutrients. When it grows into a tall plant, its roots become thick and long, with many root systems. It will cause the rock to crack and cause damage to the rock.

In nature, there are also natural disasters that can destroy rocks. For example, volcanic eruptions, earthquakes, and flash floods can turn broken large rocks into many rubbles. When water flows down from the mountains, it weathers the mountains and turns them into gravel, which is then transported to very far places by the flowing water. The speed of the flowing water is slow, and the force of transportation is reduced, especially in the middle and lower reaches of the rivers and in the river channels. Most of the rocks are carried by the river from the upper reaches. After the continuous impact of the water flow and the friction between the rocks, the edges and corners on the rocks disappeared and became very smooth, thus forming pebbles.

Types of pebbles

High-grade dyed sand for decorative materials such as natural color cobblestones, river pebbles, rainstones, dry-stick stones, spray-painted cobblestones, landscaping stones, petrified wood, cultural stones, etc. It is non-toxic, odorless and does not discolor. It is a natural stone with hard quality, bright and simple color, and has the characteristics of pressure resistance, wear resistance and corrosion resistance. It is an ideal green building material.

Part Three: Small Problems

What are the experimental steps for pebbles?

Answer: Find a piece of shale, first put it in the fire, then quickly put it into cold water, repeat this several times. At this time, these rocks become very soft, and a piece can fall off when touched with your hand. Because hard rocks have been exposed to wind, rain, and sun for many years, over a long, long time, the cracks will gradually become larger and larger, so that the big rocks will become smaller ones.

What types of pebbles are there?

Answer: Cobblestones, river pebbles, rain flower stones, dry-stick stones, spray-painted cobblestones, landscaping stones, petrified wood, and cultural stones.

Are there any natural disasters in nature that can destroy rocks?

Answer: Volcanic eruptions, earthquakes, flash floods, plants.

Keywords: Free download of Qingdao edition fifth grade science PPT courseware for the second volume, Make a Pebble PPT courseware, .PPT format;

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"Making a Pebble" PPT courseware:

"Making a Pebble" PPT Courseware Part One: Characteristics of Pebbles Regardless of size, pebbles are shaped like bird eggs, smooth and round. Simulation experiment: Make a pebble. Experimental equipment and materials: alcohol lamp, sink, tweezers, matches, transparent plastic bottle, broken bricks, water, solid...

"Make a Pebble" PPT:

"Making a Pebble" PPT Part One: The Formation of Pebbles (1) Have you ever seen a pebble? What do they look like? Observe the pictures and objects and talk about the characteristics of the pebbles. Characteristics of pebbles: Pebbles, regardless of size, are all shaped like bird eggs, smooth and round. ..

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Update Time: 2024-11-16

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