Question

what is the effect of decrease of pressure to one atmosphere on solid carbon dioxide? which phenomenon is related with it?

Answer 1

The effect of lowering pressure to one atmosphere on solid carbon dioxide, dry ice, is that it will directly changes its state from solid to gas. 
This phenomenon is referred to as sublimation. It is the process by which a solid object directly transforms to a gas, without passing through the liquid state.

Answer 2

solid carbon dioxide is called as dry ice and a decrease in pressure up to 1 atm will convert it into gaseous carbon dioxide , the phenomenon is called as sublimation.