Question

on monday, tyler put a 50-gram ice cube in a 50-gram cup. together, the mass was 100 grams. he left the cup at room temperature. when tyler came back on thursday, he saw that the cup now had liquid water in it, not ice. the total mass of the water and cup was 70 grams. which statement explains the change in mass? the ice cooled the cup down, so the cup lost mass. then, the ice melted into water. the ice melted into liquid water. then, some of the water evaporated. the cup warmed up as it sat on the counter. also, some water vapor condensed into the cup.

Explanation:

1. Analyze the first option: Cooling a cup doesn't make it lose mass (mass of a solid object like a cup doesn't change with temperature in this context), so this is incorrect.
2. Analyze the second option: Ice melts to water (phase change, mass of water from melted ice is same as ice initially), but then if some water evaporates (turns to water vapor and leaves the cup), the total mass (water + cup) would decrease. Initially total mass was 100g (50g ice +50g cup), later 70g. So ice melting then water evaporation (losing mass as vapor) explains the decrease.
3. Analyze the third option: Condensing water vapor into the cup would increase mass, but the total mass decreased (from 100g to 70g), so this is incorrect.

Answer:

The ice melted into liquid water. Then, some of the water evaporated.