Determination for the modal age level for grades seven and nine of the difficulty of the principle: gases, liquids and solids expand when heated and contract when cooled.

Creighton, William Andrew2016-03-032016-03-0319531953b1467581xhttps://hdl.handle.net/2144/14985Thesis (Ed.M.)--Boston Universityen-USBased on investigation of the BU Libraries' staff, this work is free of known copyright restrictions.Determination for the modal age level for grades seven and nine of the difficulty of the principle: gases, liquids and solids expand when heated and contract when cooled.Thesis/Dissertation