Answer:
The amount of matter stays same as water changes state.
Step-by-step explanation:
When water changes its state, inner composition and arrangements of molecule will change but amount of matter stays same. when water from its liquid state changes to solid movement of molecule is almost zero. and arrangement of molecules is stable( in case of water, density of its liquid state is more than its solid state). When water convert in gaseous state randomness of molecules increase but amount of matter remains same.