What defines temporary hardness in water?

Temporary hardness in water is primarily defined by the presence of bicarbonate ions, which can be removed through boiling the water. When water containing these bicarbonate ions is heated, the bicarbonates decompose to form carbonate ions, which react with calcium and magnesium to form insoluble precipitates. This process effectively removes the hardness from the water.

The other options describe characteristics that do not accurately represent temporary hardness. For instance, methods other than boiling would not be effective specifically for temporary hardness, and the statement that it cannot be removed at all contradicts the very definition, as boiling is a straightforward method to eliminate this type of hardness. Additionally, while dissolved minerals do contribute to both temporary and permanent hardness, temporary hardness specifically refers to those that can be removed by boiling, rather than being solely attributed to dissolved minerals.