In the crown-ether complex, the metal ion fits into the cavity of the crown ether and is solvated by the oxygen atoms. The exterior of the complex is nonpolar, masked by the alkyl groups of the crown ether.
Arrow Alerts. Location-enabled apps and services track your iPhone by periodically querying it for location-based information. They may do this while being used or running in the background on your device. A little arrow appears on the iPhone's upper-right corner to advise you when data is shared. Arrows also appear within the Location Services settings screens to indicate when and what kinds of information was shared with whom.
An arrow is a graphical symbol such as â or â, used to point or indicate direction, being in its simplest form a line segment with a triangle affixed to one end, and in more complex forms a representation of an actual arrow. The direction indicated by an arrow is the one along the length of the line towards the end capped by a triangle. The typographical symbol developed in the 18th century as an abstraction from arrow projectiles. Its use is comparable to that of the older manicule ...