What non metal is a liquid at 20degrees?
The only non-metal element that is a liquid at room temperature I know of is Bromine of group 7.
mixture in what state u want to know?? gaseuos, liquid or solid?? if gaseous, commonly we use burning, or absorption method. if liquid, non metal with non metal, or non metal with metal by using electrolysis to separate. if in solid metal with non metal, use magnet. as such, salt water, boiling, filtration is involved.