This exchange of gases occurs rapidly (fractions of a second). The carbon dioxide then leaves the alveolus when you exhale and the oxygen-enriched blood returns to the heart. Thus, the purpose of breathing is to keep the oxygen concentration high and the carbon dioxide concentration low in ...
How do air masses move? What distinguishes trace gases from aerosols? Explain in detail the mechanism for gas exchange What are some conditions that can affect the diffusion of pulmonary gases? How does water vapor get into the atmosphere?
Why do objects float in liquids denser than themselves? Explain the elastic properties of a matter on the basis of interatomic forces. Describe matter waves. Explain why the velocity of sound is greater in solids than in gases. Why can't all materials become superconductors?
How do solids, liquids, and gases differ? Drag the appropriate descriptions to their respective bins. Reset Help The particles pack relative close to one another, but their attractions allow Although the particles vibrate, they do them to move relati...
How do you make eggs easier to peel?The million-dollar question! There are many theories on how to makehard-boiled eggs easier to peelsuch as using eggs that are at least 10 days old, adding baking soda or vinegar to the water, and placing the eggs in an ice water bath. After trying...
This piston is very loose in its cylinder, so air can move easily between the heated and cooled sections of the engine as the piston moves up and down. The displacer moves up and down to control whether the gas in the engine is being heated or cooled. There are two positions: When ...
It is important to plan your move before heading out as it may help you avoid making several small trips. A car’s engine cools down when parked for few hours, thus uses more fuel for the first few miles. Combining all your daily chores together may therefore help in saving money on g...
Although holograms don't currently move like they do in the movies, researchers are studying ways to project fully 3-D holograms into visible air. In the future, you may be able to use holograms to do everything from watching TV to deciding which hair style will look best on you. To ...
They give off a lot of greenhouse gases (温室气体)(especially CO2) into the air. This warms the earth. As a result, many animals are dying out, (A)___as penguins (企鹅)and polar bears. It will soon make a difference to us as well. (D) Sea levels will rise and many cities a...
The gases, which rise through the air, make up the flame. Carbon atoms rising in the flame emit light as they heat up. (Check out How Light Bulbs Work to find out why heated objects emit light.) The heat of the flame keeps the fuel at the ignition temperature, so it continues to ...