Question

at a concert or special event you may have seen a thick smoke used for effect the somke is produced because a solid is converted into a gas directly name the solid and the process

Answer 1

CO2 jets, sometimes called cryo FX Or sometimes Dry ice

and process is called Sublimation

Dry Ice is basically supercooled CO2 so room temperature and normal pressure (atmospheric pressure), carbon dioxide is usually a gas. So when you take dry ice (solid carbon dioxide) and expose it to this temperature and pressure, it will try to return to the gas phase.