They're called resin identification codes, and they indicate the type of plastic that an item is made from. These numbers alone do not indicate whether a package is recyclable, but can be used in conjunction with instructions from your community to help you know the types of plastics can be recycled where you live.
I would say that the Rocky Mts were the youngest of all these mountain ranges as they were created between 80-55 million years ago during the Laramide Orogeny and also they are generally much taller than the other mountain ranges mentioned here which is a characteristic of young mountain ranges and their features are sharper as they haven't been eroded the way most of these others have so have been subject to erosion for less time than the others.
Organized nationalist army and led insurgency, Guided Turkey from "Ottomanism" to "Turkishness"; separation of church and state; replaced Muslim calendar with Gregorian; purified/modernized Turkish language
hope this helps :)