2.23 升华
Section outline
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Rock bands often use special stage effects, like the fake fog in this picture. Real fog forms when water vapor in the air condenses into tiny droplets of water. The fake fog shown here formed when carbon dioxide changed directly to carbon dioxide .
::岩石带通常使用特殊的舞台效应,如照片中的假雾。当空气中的水蒸发体凝结成小滴水时,真正的雾形成。当二氧化碳直接变成二氧化碳时,这里所显示的假雾形成。How Sublime!
::多么高尚!Solid carbon dioxide is also called dry ice. That’s because when it gets warmer and changes state, it doesn’t change to a by . Instead, it changes directly to a gas without going through the liquid state. The process in which a solid changes directly to a gas is called sublimation . It occurs when is added to a solid such as dry ice.
::固态二氧化碳也被称为干冰。 这是因为当它变暖和变化状态时,它不会变成一个状态。 相反,它会直接改变为气体而不经过液态。 气体的固态变化过程被称为升温。 当它被添加到干冰等固态时,它就会发生。Q: Alyssa’s mom put some mothballs in her closet in the spring to keep moths away from her wool clothes. By autumn, the mothballs were much smaller. What happened to them?
::问题:Alyssa的妈妈在春天的衣柜里放了一些飞蛾球,以使飞蛾远离羊毛衣。 到秋天,飞蛾球小得多。 它们怎么了?A: Mothballs are made of naphthalene, a substance that undergoes sublimation at room . The solid mothballs slowly changed to a gas during the summer months, explaining why they were much smaller by autumn.
::甲:分子球是由氯化萘制成的,该物质在室内被升华。在夏季几个月里,固态的蛾子球慢慢地变成了一种气体,解释了为什么它们到秋天会变小得多。Sublimation of Snow and Ice
::雪和冰的升华Snow and ice may also undergo sublimation under certain conditions. This is most likely to happen where there is intense sunlight, very cold temperatures, and dry winds. These conditions are often found on mountain peaks. As snow sublimates, it gradually shrinks without any runoff of liquid water.
::在某些条件下,雪和冰也可能会升华。 在阳光炎热、气温非常寒冷和风干的地方,这种情况最有可能发生。这些条件经常出现在山峰。随着雪的升温,它会逐渐缩小,而没有水分径流。Summary
::摘要-
Sublimation is the process in which a solid changes directly to a gas without going through the liquid state. Solid carbon dioxide is an example of a substance that undergoes sublimation.
::升华是一个过程,在这个过程中,一种气体在不经过液体状态的情况下直接发生固态变化。 固态二氧化碳是某种物质被升华的一个例子。 -
Snow and ice undergo sublimation under certain conditions. This is most likely to happen where there is intense sunlight, very cold temperatures, and dry winds.
::在某些条件下,雪和冰会升华。在阳光炎热、非常寒冷的温度和干风的地方,这种情况最有可能发生。
Review
::回顾-
What is sublimation? Give an example.
::什么是升华?举个例子。 -
Describe conditions under which snow or ice is most likely to undergo sublimation.
::描述雪或冰最有可能升华的条件。 -
The plastic container pictured in the
Figure
is filled with solid air freshener. The solid gradually shrinks after the holes in the top of the container are opened. Explain why this occurs.
::图中描绘的塑料容器装有固体空气清新剂,在打开容器顶部的洞口后,固体逐渐缩缩,解释为什么会发生这种情况。
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Sublimation is the process in which a solid changes directly to a gas without going through the liquid state. Solid carbon dioxide is an example of a substance that undergoes sublimation.
