Surface tension is caused by the attraction of the particles in the surface layer by the bulk of the liquid.
Good luck i can't view the link, but I really hope you can get the answer
The weather man said the relative humidity will be high today
The mixture would be :
1. Homogeneous; dissolving followed by filtration and distillation
salt dissolve in water and will be the filtrate and chalk will be the residue in the filter paper
hope this helps