Mineral and organic soil particles tend to have charges, so they attract charged molecules and ions. the charge gradient produced in the soil solution causes charges to tend to move out of the root hairs.

Answer number 1 is: negative.
Answer number 2 is: positive.
Answer number 3 is: positive.
Mineral soil has less than 12-20% content of organic matter.
Organic soil has greater than 12-20% content of organic matter.
Root hairs form an important surface, they are important because root hairs absorb most of the water and nutrients.

Generally travels west to east but often shifts to north and south