http://www.ck12.org Chapter 2. Matter
Other substances that are normally solids on Earth can also be heated until they melt. You can see an example in
theFigure2.39. 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.
FIGURE 2.39
Melting Point
The temperature at which a substance melts is called its melting point. Melting point is a physical property of matter.
The gold pictured in theFigure2.39, for example, has a melting point of 1064°C. This is a high melting point, and
most other metals 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.
Melting and Global Climate Change
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. You can learn more about these effects of
melting at this URL: http://video.nationalgeographic.com/video/player/environment/global-warming-environment/
glacier-melt.html.
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/117720Summary
- 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.