Hello. I am preparing for certain exams and I encountered these question. Can you guys help me to solve these ones? The 1st one I tried to apply formula about density (p=m/v), but I guess that I need to solve through that ice cube. That I firstly sort out the number of atoms in ice cube and then I'll convert it into steam? I have no idea how to solve it. The second one is mostly about lever system. I tried to use the formula (m=fd), but i dont know how to put figures into it to make it stable. Does anyone have an idea? Thanks a lot!