19.a separating method which Is the volatile components is removed by evaporating leaving non-volatile components behind.
a.magnetic separation
b.decantation
c.crystallization
d.evaporation
20.sugar is heated in a test tube until it is completely changed into black mass and droplets of water this experiments indicates that sugar is________
a.an Element
b.a heterogeneous mixture
c.a compound
d.a solution​