With RRMS, the patient experiences relapses (attacks, exacerbations, or flare-ups) during which there are increased symptoms and/or a worsening of neurologic function, followed by partial or complete recovery (or remission). Much more common: RRMS is much more common than progressive courses of MS, which only affect 10% to 15% of patients.
Vapor density is the density of a vapour in relation to that of hydrogen.It may be defined as mass of a certain volume of a substance divided by mass of same volume of hydrogen. vapor density = mass of n molecules of gas / mass of n molecules of hydrogen.Therefore:vapour density = molar mass of gas / molar mass of H 2.or example, acetone has a vapour density of 2 in relation to air. That means acetone vapour is twice as heavy as air. This can be seen by dividing the molecular weight of Acetone, 58.1 by that of air, 28.97, which equals 2.
The density of air, Ï (Greek: rho) (air density), is the mass per unit volume of Earth's atmosphere. Air density, like air pressure, decreases with increasing altitude. It also changes with variation in temperature or humidity.