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.
The biggest difference between the iPhone 8, iPhone 8 Plus and iPhone X is the industrial design. Apple's lack of real advancement in design dampened the iPhone 7 and left us with a phone that felt the same as the iPhone 6. Both the iPhone 8 and iPhone X might have similar internals, but they're very different in terms of display. The iPhone X is the first of Apple's phones to ditch an IPS LCD display for OLED - the same screen tech used by Samsung and LG. OLED offers perfect blacks and much more vivid colours than LCD displays, and all the best phones use it. If you plump for the iPhone 8 or 8 Plus, you'll be stuck with the IPS LCD panels.