Melting and boiling

• Melting is when a solid turns into a liquid.
• The temperature increases thus kinetic energy in solid increases and particles vibrate more rapidly.
• When melting starts there is no increase in temperature of the substance because thermal energy supplied is being used to break bonds between particles of the solid thus making it into a liquid.
• The latent heat of fusion is the amount of energy needed to melt 1Kg of a substance
• The melting point is the temperature at which a substance liquifies
• Boiling is when a liquid turns into a gas
• The temperature increases thus kinetic energy in liquid increases and particles vibrate more rapidly.
• When boiling starts, there is no increase in temperature of the substance because the thermal energy supplied is being used to break bonds between particles of the liquid thus making it into a gas.
• The latent heat of vaporization is the amount of energy needed to boil 1Kg of a substance
• The difference between boiling and evaporation is that:

  • Boiling occurs at a fixed temperature and throughout the liquid
  • Evaporation occurs at any temperature and only on the surface
• Condensation is when a gas turns back into a liquid.
• When a gas is cooled, the particles lose energy. They move more and more slowly. When they bump into each other, they do not have enough energy to bounce away again so they stay close together, and a liquid forms.
• When a liquid cools, the particles slow down even more. Eventually they stop moving except for vibrations and a solid forms.
• Specific latent heat of fusion vaporization =  $\frac{Energy\ Transferred}{Mass}$

  or $\frac{L_f}{L_v}=$$\ \frac{E}{m}$