Jawapan

2016-09-10T20:25:58+08:00
It's because the carbon dioxide gass was released.. that's why the mass decreased
2016-09-12T08:03:04+08:00
When it is heated, the following change occurs :

CaCO₃ ---> CaO + CO₂

When calcium carbonated is heated, it decomposes into calcium oxide and carbon dioxide. Therefore, the mass of calcium carbonate decreases.