The air cell increases in size during incubation at a rate that depends on temperature and humidity as moisture evaporates from the egg. The drawing shows the normal size of an egg's air cell at 7, 14, and 18 days of incubation. Size of the air cell in the egg on the 7th, 14th, and 18th day of incubation.
A specific heat capacity is the amount of energy necessary to increase the temperature of a kilogram of that substance by one kelvin. Molar heat capacity is the amount of energy necessary to raise one mole of substance by one kelvin degree. One mole of a substance is exactly 6.02x10 23 atoms or molecules of that substance.
To boil or melt one mole of a substance, a certain amount of energy is required. These amounts of energy are the molar heat of vaporization and molar heat of fusion. If that amount of energy is added to a mole of that substance at boiling or freezing point, all of it will melt or boil, but the temperature won't change. The graph shows the temperature of ice as heat is added.