Solids can be converted to liquid on heating. Further heating changes a liquid to gas.
The temperature at which a pure solid converts to liquid is called the melting point of the solid. The temperature at which a pure liquid changes to gas is called the boiling point of the liquid.
All matter is made of particles. The way these particles are held together, determines the state of the matter. Solids have a definite shape. This implies that the particles are closely packed together by strong attractive forces between them. They are so tightly held together that the only able to vibrate about their mean positions.
As a solid is heated, the particles in it gain energy and begin to vibrate faster. Eventually a time comes when the vibration become so fast that the particles are able to break free. They become more widely spaced and begin to move more freely. As described above, the temperature at which this change occurs is called the melting point. It should be noted that when a solid reaches its melting point, its temperature would remain constant, until it has changed to liquid.
If heat energy is supplied to a liquid, the particles inside the liquid, gain energy and begin to vibrate at an even greater speed. Eventually a temperature is reached when the particles have gained sufficient energy to escape from the surface of the liquid. They then become active enough and far apart to change the state of the matter to gas.
The temperature at which a pure solid converts to liquid is called the melting point of the solid. The temperature at which a pure liquid changes to gas is called the boiling point of the liquid.
All matter is made of particles. The way these particles are held together, determines the state of the matter. Solids have a definite shape. This implies that the particles are closely packed together by strong attractive forces between them. They are so tightly held together that the only able to vibrate about their mean positions.
As a solid is heated, the particles in it gain energy and begin to vibrate faster. Eventually a time comes when the vibration become so fast that the particles are able to break free. They become more widely spaced and begin to move more freely. As described above, the temperature at which this change occurs is called the melting point. It should be noted that when a solid reaches its melting point, its temperature would remain constant, until it has changed to liquid.
If heat energy is supplied to a liquid, the particles inside the liquid, gain energy and begin to vibrate at an even greater speed. Eventually a temperature is reached when the particles have gained sufficient energy to escape from the surface of the liquid. They then become active enough and far apart to change the state of the matter to gas.
