2.19 熔化
Section outline
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The fiery red-orange “river” flowing downhill in this photo isn’t water. It’s molten (melted) rock, and it’s erupting from a volcano. Most rocks on Earth’s surface are objects. Why is the rock that erupts from a volcano in a state? How does rock change from a solid to a liquid?
::这张照片中的火热红色的“河流”在下坡流,不是水。 它是熔化的(熔化的)岩石,从火山喷发。 地球上的多数岩石都是物体。 为什么火山爆发在一个州? 岩石是如何从固体变成液体的?From Solid to Liquid
::从固体到液体The process in which rocks or other solids change to liquids is called melting. Melting occurs when particles of a solid absorb enough to partly overcome the force of attraction holding them together. This allows them to move out of their fixed positions and slip over one another. Melting, like other , is a in matter, so it doesn’t change the chemical makeup or .
::岩石或其他固体变换成液体的过程被称为熔化。 当固体吸收的粒子足以部分克服吸引力量的力量时,熔化就会发生。 这使得它们能够走出固定的位置,互相滑倒。 熔化和其他固体一样,是一个问题,因此它不会改变化学成分或化学成分。Q: The molten rock that erupts from a volcano comes from deep underground. How is this related to its liquid state?
::问题:火山爆发的熔岩来自地下深处。这与火山的液体状态有何关系?A: It is always very hot deep underground where molten rock originates. The high temperatures give rock enough energy to melt and remain in a molten state. Underground rock in this state is called magma.
::A: 熔岩的起源地总是非常深的地下。 高温使岩石有足够的能量熔化,并保持熔化状态。 这个状态下的地下岩石被称为岩浆。Q: What happens to magma after it erupts and starts flowing over the surface of the ground?
::问题:岩浆在喷发并开始流过地面之后会怎样?A: After magma erupts, it is called lava. On the surface, lava eventually cools and hardens to form solid rock.
::A:在岩浆喷发后,它被称为熔岩。在表面,熔岩最终会冷却和硬化以形成坚固的岩石。Other substances that are normally solids on Earth can also be heated until they melt. You can see an example in the Figure . The photo shows molten gold being poured into a mold. When the gold cools, it will harden into a solid gold bar that has the same shape as the mold.
::地球上通常为固体的其他物质也可以加热,直到熔化为止。您可以看到图中的例子。照片显示熔化的黄金被倒入模具。当黄金冷却时,它会硬化成一个与模具形状相同的固体金条。Melting Point
::熔点The at which a substance melts is called its melting point. Melting point is a physical property of matter. The gold pictured in the Figure , for example, has a melting point of 1064°C. This is a high melting point, and most other also have high melting points. The melting point of ice, in comparison, is much lower at 0°C. Many substances have even lower melting points. For example, the melting point of oxygen is -222°C.
::物质熔化的点被称为熔点。熔点是物质的物理属性。例如,图中的黄金熔点为1064°C。这是一个高熔点,其他大部分也有一个高熔点。相比之下,冰的熔点在0°C时要低得多。许多物质的熔点甚至更低。例如,氧的熔点是-222°C。Melting and Global Climate Change
::熔化与全球气候变化Because of global climate change, temperatures all over Earth are rising. However, the melting points of Earth’s substances, including ice, are constant. The result? Glaciers are melting at an alarming rate. Melting glaciers cause rising sea levels and the risk of dangerous river flooding on land.
::由于全球气候变化,全球气温都在上升。 然而,包括冰在内的地球物质的熔点是恒定的。 结果呢?冰川正在以惊人的速度融化。 冰川融化导致海平面上升和陆地上危险的河流洪水风险。Summary
::摘要-
Melting occurs when particles of a solid absorb enough energy to partly overcome the force of attraction holding them together. This allows them to move out of their fixed positions and slip over one another, forming a liquid.
::当固体吸收足够能量的粒子能够部分克服将它们捆绑在一起的吸引力时,就会发生熔化。 这使得它们能够走出固定位置,相互滑倒,形成液体。 -
The temperature at which a substance melts is called its melting point. The melting point of ice is 0°C.
::物质熔化的温度称为熔点。冰的熔点为0°C。
Review
::回顾-
Define melting.
::定义熔化。 -
What happens to particles of matter when it changes from a solid to a liquid?
::当物质粒子从固体变成液体时会怎样? -
What is the melting point of a substance? What is the melting point of ice?
::物质的熔点是什么?冰的熔点是什么?
Explore More
::探索更多An alloy is a mixture of a metal with one or more other substances. The following Table lists melting points of two metals and three alloys that they form together. Examine the table and then answer the questions below.
::一种合金是金属与一种或多种其他物质的混合体,下表列出了它们共同形成的两种金属和三种合金的熔点。Metal or Alloy Melting Point (°C) Iridium metal (pure) 2454 Platinum metal (pure) 1773 Platinum-iridium alloy (15% iridium) 1821 Platinum-iridium alloy (10% iridium) 1788 Platinum-iridium alloy (5% iridium) 1779 -
Based on the information in the table, what conclusion might you draw about the melting points of alloys relative to the melting points of the metals they contain?
::根据表格中的信息,你能得出什么结论来说明合金相对于其所含金属熔点的熔点的熔点? -
Bronze is another alloy. It is a mixture that contains mainly copper with some added tin. The melting point of copper is 1084°C, and the melting point of tin is 232°C. What might be a reasonable prediction for the melting point of bronze?
::铜是另一个合金。 它是一种主要含有铜和一些添加的锡的混合物。 铜的熔点是1084°C,锡的熔点是232°C。 青铜熔点的合理预测是什么?
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Melting occurs when particles of a solid absorb enough energy to partly overcome the force of attraction holding them together. This allows them to move out of their fixed positions and slip over one another, forming a liquid.
