Answer:
The mass is also half of the mass of the original piece
Step-by-step explanation:
Recall that the volume of a substance is defined as mass/volume. The density of substances is a constant. Hence, if a break off a piece of cement or bread such that what remains is only half the volume of the original piece, the mass of the new piece must also reduce to half of the mass of the original piece so that the volume of the material will remain constant.
Hence the answer above.