Section outline

  • General

    Collapse all Expand all

  • 热热热

    A blacksmith works at an anvil, shaping hot iron while sparks fly around.

    “Under the spreading chestnut tree ...” - The Village Blacksmith  by Henry Wadsworth Longfellow. 1807-1882
    ::亨利·瓦兹沃斯·朗费洛(Henry Wadsworth Longfellow)著,“在扩张的栗子树下......”

    Blacksmiths, like the one mentioned in Longfellow's poem, heat solid iron in order to shape it into a variety of different objects. Iron is a rigid, solid metal . At room temperature , it is extremely difficult to bend iron. However, when heated to a high enough temperature, iron can be easily worked. The heat energy in the forge is transferred to the metal, making the iron atoms vibrate more and move around more readily.
    ::铁匠们,就像朗费洛的诗中提到的铁匠们一样,将固体铁制成不同的铁制成不同的物体。铁是硬的、固态的金属。在室温下,铁极难弯曲。然而,当热到足够高的温度时,铁很容易工作。铁制的热能被转移到金属上,使铁原子更振动,更容易移动。

    Heat
    ::热热热

    Heat is energy that is transferred from one object or substance to another because of a difference in temperature between them. Heat always flows from an object at a higher temperature to an object at a lower temperature (see Figure ). The flow of heat will continue until the two objects are at the same temperature.
    ::热量是指因温度差异而从一个物体或物质转移到另一个物体的能量。热量总是从高温的物体流向低温的物体(见图 )。热量将持续到两个物体处于同一温度时为止。

    Heat flow from object A (hot) to object B (cold) until equilibrium.

    Object A starts with a higher temperature than object B. No heat flows when the objects are isolated from each other. When brought into contact, heat flows from A to B until the temperatures of the two objects are the same.
    ::对象 A 开始温度比对象 B 高。当对象相互隔离时,没有热流。接触时,热流从 A 流向 B ,直到两个对象的温度相同。

    Thermochemistry is the study of energy changes that occur during and during .  When chemical reactions occur, some chemical bonds are broken, while new chemical bonds form. As a result of the rearrangement of atoms, the total of the system either increases or decreases.
    ::热化学是研究在化学反应发生期间和期间发生的能量变化。当化学反应发生时,一些化学结层被打破,而新的化学结层则形成新的化学结层。由于原子的重新排列,整个系统的总数要么增加,要么减少。

     

     

    Summary
    ::摘要

    • Heat is transferred energy from a site of higher energy to a site of lower energy.
      ::热能从高能地点转移到低能地点。

    Review
    ::回顾

    1. What is heat?
      ::什么是热?
    2. In which direction does heat flow?
      ::热流流向哪个方向?
    3. What does thermochemistry involve?
      ::热化学涉及什么?