"Air" The air around us PPT courseware 7

Description

"Air" The air around us PPT courseware 7

Air is a precious resource:

1. The purpose of oxygen: It used to be called "nourishing Qi"

(1) Supply breathing

(2) Support burning

2. Uses and properties of nitrogen

Discussion: P29

1. Nitrogen cannot support combustion.

2. The water surface will not continue to rise, indicating that nitrogen is not easily soluble in water.

3. Some properties of nitrogen can only be explained to a certain extent. For example, air is not easily soluble in water, which is consistent with nitrogen, but air can support combustion and breathing, but nitrogen cannot.

Summary of the properties of nitrogen: colorless, gas, odorless, low density, low melting and boiling point, not easily soluble in water, cannot burn, and does not support combustion.

3. Properties and uses of rare gases

(1) Rare gases are the general name (mixture) of gases such as helium, neon, argon, krypton, and xenon.

(2) Rare gases are colorless, odorless, and very inactive chemically.

(3) Purpose: protective gas, electric light source laser technology, low temperature anesthesia

3. Protect the air

1. Harmful substances emitted into the air and their sources

2. Dangers of air pollution:

It will seriously damage human health, affect crop growth, and destroy ecological balance.

3. Three major environmental issues

Greenhouse effect Increased CO2 content

Ozone hole Freon etc.

Acid rain SO2, NO2, etc.

4. Methods to protect the air:

Strengthen air quality monitoring, improve environmental conditions, use clean energy, and actively plant trees, afforestation, grass, etc.

Summary

After studying this topic you should know

1. The composition of air by volume is approximately: 21% oxygen, 78% nitrogen, 1% rare gases, etc.

2. A pure substance consists of one substance; a mixture consists of two or more substances. Oxygen, nitrogen, etc. are pure substances, and air is a mixture.

3. Air is a precious natural resource, and air pollution must be prevented.

Practice in class:

1. The composition of air is calculated by volume. Which of the following conclusions is incorrect ( )

A. Nitrogen accounts for 78% B. Other gases and impurities account for about 0.03%

C. Carbon dioxide accounts for 0.94% D. Oxygen accounts for 21%

2. The respiration of humans and other animals and plants and the burning of fuel consume a large amount of ( )

A. Nitrogen B. Oxygen C. Carbon dioxide D. Rare gas

3. The gas in the air that can make clear lime water turbid is ( )

A. Nitrogen B. Oxygen C. Carbon dioxide D. Rare gas

4. Which of the following processes will not cause air pollution ( )

A. Carbon dioxide exhaled by humans and animals

B. Smoke produced by coal burning

C. Smoke emitted from car exhaust

D. Waste gas emitted from petrochemical plants

Keywords: Air around us teaching courseware, air teaching courseware, People's Education Edition ninth grade chemistry PPT courseware download, ninth grade chemistry slide courseware download, air around us PPT courseware download, air PPT courseware download, .PPT format;

For more information about "The Air Around Us" PPT courseware, please click on the Air Around Us ppt air ppt tag.

"Thermal Expansion and Contraction of Air" thermal PPT download:

"Thermal Expansion and Contraction of Air" Hot PPT Download Part One: Exploring New Knowledge Observing whether the air expands and contracts with heat. Hypothesis: Air has the property of thermal expansion and contraction. If the volume of the air inside the bottle expands, the air inside the bottle will be squeezed out. Just find a way to observe inside the bottle...

"Thermal Expansion and Contraction of Air" Hot PPT:

"Thermal Expansion and Contraction of Air" Thermal PPT Part One Content: Observe whether the air expands and contracts with heat. Water and many liquids have the property of thermal expansion and contraction. Will air expand with heat and shrink with cold? Put air in a bottle to heat or cool the air inside the bottle. Just look inside the bottle...

"The Air Around Us" Water and Air PPT:

"The Air Around Us" Water and Air PPT Part One: The Air We Know Without opening the bag, we found the bag containing air. On what basis do we discern? What do we know about air? ... ... ..

File Info

Update Time: 2024-07-01

This template belongs to Chemistry courseware People's Education Press Ninth Grade Chemistry Volume 1 industry PPT template

Preview