Final answer:
The mass of the liquid water after the ice completely melts will be 100 g, consistent with the law of conservation of mass.
Step-by-step explanation:
When a student adds 100 g of ice to a bowl and allows the ice to melt into liquid water completely, the mass of the liquid water will be 100 g. This is due to the law of conservation of mass which states that mass is neither created nor destroyed in a chemical reaction or physical transformation, which melting is. In the absence of any other factors, such as evaporation or additional water being added, the mass of the melted ice will remain the same as the original mass of the ice.