One because Potassium is in the first column on the periodic table. Any element in the first column on the periodic table has one valence electron in their outer shell.
Angiosperms didn't exist until the late Mesozoic era..
The correct answer is A. T<span>rapping of heat by water vapor and gases in the atmospere. The sun gives off short-wave radiation, which is then absorbed by the atmosphere, which keeps us nice and cozy here on Earth! </span>