A chemical property is a characteristic of a pure substance that describes its ability to change into different substances. For example, a chemical property of methane is that it can catch fire and burn in air. Physical properties can be observed or measured without changing the composition of matter.
The downsides are obvious: Almost everyone has headphones, speakers, and other gadgets based on the ubiquitous 3.5 mm headphone jack. Eliminating this connection could render these devices unusable, or at least force everyone to carry around an extra adapter. But Apple doesnât care.
These 3.5mm adapters will allow one to use standard headphones with the smaller jack. The opposite type of adapter is also available, with a 3.5mm female socket on one end, and a 1/4-inch pin on the other. This allows 3.5mm headphones to be used in jacks made for larger headphones.