We can detect the hardness of water taken from different sources by adding soap to it. If the soap does not form micelle in the water then it will be hard water. In simple language if the soap doesnot disslove in water then it will be soft water.
Answer:
4 Charles Darwin was not able to explain the variation
Answer:
As a cell grows bigger, its internal volume enlarges and the cell membrane expands. Unfortunately, the volume increases more rapidly than does the surface area, and so the relative amount of surface area available to pass materials to a unit volume of the cell steadily decreases.
