交存
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The leaf-like pattern on the glass pictured here is as beautiful as any work of art. It formed on a windowpane on a very cold winter night. Do you know how it formed? The answer is deposition.
::这里所拍摄的玻璃上像叶一样的图案与任何艺术品一样美丽。 它形成于一个寒冷的冬季夜晚的窗帘上。 你知道它是如何形成的吗? 答案是沉积。What Is Deposition?
::什么是沉积?Deposition refers to the process in which a changes directly to a without going through the state. For example, when warm moist air inside a house comes into contact with a cold windowpane, water vapor in the air changes to tiny ice crystals. The ice crystals are deposited on the glass, often in beautiful patterns like the “leaves” on the window above. Be aware that deposition has a different meaning in Earth science than in chemistry . In Earth science, deposition refers to the dropping of sediments by wind or water, rather than to a .
::沉积是指直接改变状态的过程。 比如,当房屋内温暖的潮湿空气与寒冷的窗玻璃接触时,空气中的水蒸气会改变微小的冰晶。冰晶会沉积在玻璃上,通常以上面窗户上的“叶子”等美丽模式存在。请注意沉积在地球科学中的意义不同于化学。在地球科学中,沉积是指通过风或水沉积的沉积物,而不是一种沉积物。Examples of Deposition in Nature
::自然沉积实例Deposition as a change of state often occurs in nature. For example, when warm moist air comes into contact with very cold surfaces—such as the ground or objects on the ground—ice crystals are deposited on them. These ice crystals are commonly called frost. Look at the dead leaf and blades of grass in the Figure . They are covered with frost. If you look closely, you can see the individual crystals of ice.
::例如,当温暖的潮湿空气与非常寒冷的表面接触时,例如地面或地面上的物体,冰晶就会沉积在它们身上。这些冰晶通常被称为冰霜。看看图中的枯叶和草叶。它们被霜霜覆盖。如果你仔细看一看,你可以看到冰的个别晶体。Q: In places with very cold winters, why might frost be more likely to form on the ground in the fall than in the winter?
::问:在寒冬非常寒冷的地方,为什么秋天在地面比冬天更可能形成霜冻?A: Frost forms when the air is warmer than the ground. This is more likely to be the case in the fall. In the winter, the air is likely to be as cold as the ground.
::A: 当空气比地面温暖时, 冰霜会形成。 秋天的情况更可能如此。 在冬天, 空气可能和地面一样寒冷 。Deposition also occurs high above the ground when water vapor in the air changes to ice crystals. In the atmosphere, the ice crystals are deposited on tiny dust particles. These ice crystals form clouds, generally cirrus clouds, which are thin and wispy. You can see cirrus clouds in the Figure .
::在大气中,冰晶沉积在微小的尘粒上,这些冰晶形成云,通常是云层云,云层是薄的、微弱的。您可以看到图中的气流云。Q: Cirrus clouds form only at altitudes of 6 kilometers or higher above sea level. Do you know why?
::问题:星云只在海拔6公里或6公里以上的高度形成。你知道原因吗?A: At this altitude, the atmosphere is always very cold. Unless the air is cold, water vapor will condense to form water droplets instead of ice crystals.
::A:在这一高度,大气总是非常寒冷。除非空气是冷的,否则水蒸气会凝结成水滴,而不是冰晶。Summary
::摘要-
In chemistry, deposition refers to the process in which a gas changes directly to a solid without going through the liquid state.
::在化学中,沉积是指气体直接转化为固体而不经过液体状态的过程。 -
Examples of deposition in nature include frost forming on the ground and cirrus clouds forming high in the atmosphere.
::自然沉积的例子包括地面形成霜冻和大气中高温形成螺旋云。
Review
::回顾-
What is deposition, as defined in chemistry?
::化学定义的沉积是什么? -
Describe an example of deposition in nature.
::描述一个证词性质的例子。 -
Tom, pictured in the
Figure
, started to scrape frost off his windshield before driving to school on a cold morning. Then he decided to let the car’s defroster do the work for him. What conditions caused the windshield to become covered with frost, and how does the defroster clear the frost from the windshield?
::汤姆,如图所示,在寒冷的早晨开车上学前开始从挡风玻璃上刮霜。 然后,他决定让汽车的除霜器为他工作。 是什么条件导致挡风玻璃被冻住了,以及除霜器如何从挡风玻璃上清除冻霜?
Explore More
::探索更多Watch the video below , and then answer the questions that follow.
::观看下面的录像,然后回答下面的问题。-
What is dry ice? What gas is used to make dry ice?
::什么是干冰 哪些气体用来制造干冰 -
In making dry ice with a fire extinguisher, why is it necessary to have a bag to collect the dry ice?
::在用灭火器制造干冰时,为什么必须有一个袋子来收集干冰? -
How can dry ice be changed back to a gas?
::怎样才能把干冰改成气体呢?
Resources
::资源 -
In chemistry, deposition refers to the process in which a gas changes directly to a solid without going through the liquid state.
