States of Matte
既然整天不思进取，浑浑噩噩，没有半点目标可言，就不要做什么英雄式的梦，好好地甘于平庸。即要前程似锦，又要毫不费力，你咋不上天？
周五
Level3-Unit2-Part1-[1]listening:States of Matter
1. Matter is made of atoms原子 and molecules分子.
2. Water, for example, is the H2O molecule.
3. This means that a molecule of water have 3 atoms.
4. A water molecule has 2 hydrogen氢 atoms and 1 oxygen氧 atom.
5. Substances like sugar have many atoms in their molecules.
6. A molecule of sugar has many atoms, including carbon碳, hydrogen and oxygen.
7. Matter is made of molecules, such as H20, which is the water molecule.
8. Matter物质 can be in one of three states: solid, liquid or gas.
9. Water and ice are the same substance, but they are in different states状态.
10. These states depend on the temperature of the molecules.
11. When we heat a substance, the molecules move faster and try to take up more space. 占用更多空间
12. When we cool substances, the molecules move more slowly.
13. When we cool a substance to its freezing point 冰点, it becomes a solid.
14. In a solid, the molecules move very little.
15. Their positions 位置 are almost fixed 固定的.
16. To be fixed means that their positions don’t change.
17. If we heat the molecules, they move faster and away from each other.
18. The solid begins to melt, like ice cream on a hot day.
19. At a certain temperature, a solid begins to change into a liquid.
20. The temperature at which a solid changes into a liquid depends on the substance.
21. For water, the solid begins to change into a liquid when its temperature rises to about 0 degree Celsius.
22. For some substances, such as steel, the temperature at which it becomes a liquid is much higher.
23. Steel often melts at around 1370 degrees Celsius.
24. If we continue to heat a liquid, the molecules move even faster.
25. At a certain temperature, the liquid begins to change into a gas.
26. For water, the liquid begins to change into a gas at 100 degrees Celsius摄氏度.
27. That is the boiling point of water.
28. Inside a star, such as our Sun, the temperature is very high.
29. Everything inside the Sun is a gas.
30. According to scientists, there are over 65 elements元素 inside the Sun.
31. These include oxygen氧 and iron.
