The answer is (4) at the cathode, where reduction occurs. The Na+ gains one electron and become Na(l). So the reaction occurs at cathode and is reduction reaction.
The minerals in hard water react with soap and affect its cleaning capacity. It's still possible to use hard water when washing by using more soap. The additional soap will no longer be affected by the minerals in the water, so they can clean just as effectively, but you'll be wasting more soap this way.
Answer:
Condensation methods from colloidal particles by aggregation of molecules or ions. Examples of colloids are really in common in evryday life, eg. Mayonnaise, butter, milk, gelatin, paper etc..
Every colloid consists of two parts :colloidal particles and the dispersing medium.
