coprecipitation is what it is called when it goes from a solid to a gas.
what is it called when it goes from a solid to a gas?
coprecipitation
sublimation is the transition of a substance directly from the solid to the gas phase, without passing through the intermediate liquid phase. sublimation is an endothermic process that occurs at temperatures and pressures below a substance's triple point in its phase diagram, which corresponds to the lowest pressure at which the substance can exist as a liquid. the reverse process of sublimation is deposition or desublimation, in which a substance passes directly from a gas to a solid phase. sublimation has also been used as a generic term to describe a solid-to-gas transition (sublimation) followed by a gas-to-solid transition (deposition). while a transition from liquid to gas is described as evaporation if it occurs below the boiling point of the liquid, and as boiling if it occurs at the boiling point, there is no such distinction within the solid-to-gas transition, which is always described as sublimation.
sublimation (phase transition)
streaming instabilities form when the solid particles are moderately coupled to the gas, with stokes numbers of 0.01 - 3; the local solid to gas ratio is near or larger than 1; and the vertically integrated solid to gas ratio is a few times solar. the stokes number is a measure of the relative influences of inertia and gas drag on a particle's motion. in this context it is the product of the timescale for the exponential decay of a particle's velocity due to drag and the angular frequency of its orbit. small particles like dust are strongly coupled and move with the gas, large bodies such as planetesimals are weakly coupled and orbit largely unaffected by the gas. moderately coupled solids, sometimes referred to as pebbles, range from roughly cm- to m-sized at asteroid belt distances and from mm- to dm-sized beyond 10 au. these objects orbit through the gas like planetesimals but are slowed due to the headwind and undergo significant radial drift. the moderately coupled solids that participate in streaming instabilities are those dynamically affected by changes in the motions of gas on scales similar to those of the coriolis effect, allowing them to be captured by regions of high pressure in a rotating disk. moderately coupled solids also retain influence on the motion of the gas. if the local solid to gas ratio is near or above 1, this influence is strong enough to reinforce regions of high pressure and to increase the orbital velocity of the gas and slow radial drift. reaching and maintaining this local solid to gas at the mid-plane requires an average solid to gas ratio in a vertical cross section of the disk that is a few times solar. when the average solid to gas ratio is 0.01, roughly that estimated from measurements of the current solar system, turbulence at the mid-plane generates a wavelike pattern that puffs up the mid-plane layer of solids. this reduces the solid to gas ratio at the mid-plane to less than 1, suppressing the formation of dense clumps. at higher average solid to gas ratios the mass of solids dampens this turbulence allowing a thin mid-plane layer to form. stars with higher metallicities are more likely to reach the minimum solid to gas ratio making them favorable locations for planetesimal and planet formation.
streaming instability