Answer: <u>A metal </u>is rare on Earth but relatively abundant in iron-rich meteorites. It has been found in widespread layers on Earth and it's date of deposition coincides with the major extinction of life on Earth 65 million years ago, possibly indicating a connection between a large impact and this extinction.
Explanation: That metal would be iridium
As you increase in elevation, there is less air above you thus the pressure decreases. As the pressure decreases, air molecules spread out further (i.e. air expands) and the temperature decreases. If the humidity is at 100 percent (because it's snowing), the temperature decreases more slowly with height.
There are 19,354 cities in the U.S.A