Strep throat Strep throat is a throat infection causing symptoms including a red sore throat with white patches. Hay fever Hay fever, an allergic reaction to outdoor pollens and molds, causes nasal congestion, itchy eyes, and more.
Air Density is the mass per unit volume of the air. For example, the standard air density at sea level is 1.225 kg/m 3 (0.076474 pounds/ft 3). Relative Density is the ratio of the actual air density to the standard sea level density, expressed as a percentage.
Answer 3: Air is a mixture of gases, primarily nitrogen and oxygen. Oxygen is denser than both air and nitrogen, at all temperatures and pressures, but only slightly. Since they don't separate from each other, we generally don't worry which is lighter or heavier. The difference in the density of nitrogen and oxygen gas comes from their molecular weight, which is small (4 g/mol).