A mule is a cross between a donkey and a horse. Therefore, a mule will have some donkey characteristics such as large ears, a head just a bit too large for its body, a skimpie â¦ r tail, some still have the cross on their backs from the donkey, and they often have small looking feet.
Density of air. The density of air, Ï (Greek: rho) (air density), is the mass per unit volume of Earth's atmosphere, and is a useful value in aeronautics and other sciences. Air density decreases with increasing altitude, as does air pressure. It also changes with variances in temperature or humidity.
DENSITY is a physical property of matter, as each element and compound has a unique density associated with it. Density defined in a qualitative manner as the measure of the relative heaviness of objects with a constant volume. For gases the density may vary with the number of gas molecules in a constant volume. Density Comparison to Air: The density of several gases is compared to the density of air. Does an object float in air or sink in the air? If an object containing a gas floats on air, it is less dense than air vs. if it sinks, it is more dense than air. Gas Density examples based upon differences in molecular weight. Density of a gas with a constant number of molecules in a constant volume, varies according to the molecular weight. The higher the molecular weight the higher the density. Helium balloon: Compare the behavior of a helium filled balloon with that of an air filled balloon.