Student X heats some water in an open beaker. Student Y heats the same mass of water in a sealed flask.
Both students measure the mass of their apparatus and water before and after heating.
Only Student X records a decrease in mass.
Which statement explains this?
Water particles escape from the open beaker but are trapped in the flask
Water particles lose mass when they evaporate, but only in the open beaker
The water in the sealed flask cannot evaporate, because the flask is sealed
The flask is heated less strongly, so less water evaporates from it
44 exam-style questions on OCR GCSE Physics 1.2 Changes of state, covering 1.2.1 Conservation of mass during changes of state, 1.2.2 Physical and chemical changes, 1.2.3 Heating, temperature and changes of state, 1.2.4 Specific heat capacity and specific latent heat, 1.2.5 Internal energy and temperature change, and 1.2.6 Energy transfer during a change of state. Each one has a worked solution and a mark scheme showing where the marks go.