Why are polar bears listed as a threatened species?

Because their species is in danger of going extinct

Because of global warming, as our ozone layer gets disrupted the ice caps are melting and the polar bear have no where to go

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.