"The Journey of Little Water Drop" PPT

Description

"The Journey of Little Water Drop" PPT

Part One: Problem Introduction

Question: What state of water do they belong to?

fog, clouds, rain, dew, frost, snow

How are clouds and fog formed?

Why is there rain and snow?

How are dew and frost formed?

Part 2: The formation of clouds and fog

How clouds and fog are formed

The cause of fog: At night, because there is no sunlight, the earth dissipates heat quickly. In the morning, the temperature near the ground is relatively low. At this time, if there is more water vapor in the air, it will condense into many small water droplets when it is cold, gather together, and float in the low altitude. This is fog.

Causes of cloud formation: Water vapor enters the atmosphere from the earth's surface and gradually rises to high altitudes. Due to the low atmospheric temperature at high altitudes, the water vapor in the air condenses into small water droplets or small ice crystals, which gather together to form clouds.

Similarities and differences in the causes of clouds and fog

Clouds and fog are similar in that they are both processes in which water vapor liquefies into small water droplets when cooled.

The difference between the formation of clouds and fog: clouds form at high altitudes, and fog forms at low altitudes.

What impact do clouds and fog have on human life?

Clouds: Affect light and form rain, snow and hail. Observe changes in clouds to predict weather.

Fog: affects traffic and human health.

Part Three: Rain and Snow

Why does it rain and snow?

What are the characteristics of the weather before it rains? Guess: What does this indicate about the formation of rain?

What phenomenon in life is similar to rain?

Running water on the steamer, tiles or mirror in the bathroom

Causes of rain and snow

The cause of rain: small water droplets or small ice crystals in the clouds gather more and more and get bigger. When the clouds cannot support them, they fall. During the falling process, when the low air temperature is above 0℃, what falls is rain. .

The cause of snow: small water droplets or small ice crystals in the clouds gather more and more, and get bigger. When the clouds are too big to hold them, they fall. During the landing process, when the low air temperature is below 0℃, what falls is snow. .

Part Four: Empathy Exploration

What are the causes of frost and dew and their impact on human life?

Frost: Water vapor in the air near the ground condenses into small ice crystals that adhere to the ground and plants. Freezing disaster.

Dew: Water vapor in the air near the ground liquefies into small water droplets on plants when cooled. Providing water to plants in water-scarce areas

water cycle in nature

Thinking: It rains and snows every year, why can’t all the water in the sky fall?

Discussion: Based on the knowledge of the three-state changes of water and the causes of clouds, fog, rain and snow, think about how water circulates in nature?

Keywords: Free download of Qingdao version of fourth-grade science PPT courseware, Volume 1 science PPT courseware, Little Water Drop’s Travel PPT download, .PPT format;

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Update Time: 2024-07-03

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

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