What type of water forms scum with soap?

consider the following statements 1) Hard water forms scum with soap. 2) Hard water lathers easily with soap 3) Hard water is unsuitable for laundry and boilers which of the following statement (s) given above is/are correct ?

Hard water forms scum with soap, due to the presence of

What did you observe while applying soap on the body? What types of chemicals are in the soap?

Why does hard water not form lather with soap ?