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.
relative density of a substance is defined as the ratio between the density of the substance to the density of water at 40c relative density is also known as specific gravity the relative density of a substance is a pure number without any unit it tells how many times a substance is heavier than water relative density r d of a substance can be calculated by dividing density of a substance with the density of water