metaphor noun [C or U]. C2 an âexpression, often âfound in âliterature, that âdescribes a âperson or âobject by referring to something that is âconsidered to have âsimilar âcharacteristics to that âperson or âobject: The âmind is an âocean and the âcity is a âjungle are both metaphors.
A precipitate is an insoluble solid that emerges from a liquid solution. The emergence of the insoluble solid from solution is called precipitation. Often the precipitate emerges as a suspension.recipitates can form when two soluble salts react in solution to form one or more insoluble products-as discussed in the famous example below.
Amorphous calcium phosphate (ACP or ATCP) is a glassy precipitate of variable composition that is formed in double decomposition reactions involving a soluble phosphate and calcium salts (e.g. (NH 4) 2 HPO 4 + Ca(NO 3) 2) performed under carefully controlled pH conditions.morphous calcium phosphate (ACP or ATCP) is a glassy precipitate of variable composition that is formed in double decomposition reactions involving a soluble phosphate and calcium salts (e.g. (NH 4) 2 HPO 4 + Ca(NO 3) 2) performed under carefully controlled pH conditions.