3reasons why japan is so densely populated?

Japan is densely populated because it is an island nation which means that there is not a lot of territory for the Japanese to spread out and inhabit. In addition Japan has a large population for the small territory that exists. A final reason is that much of life in Japan is centered around urban zones, which means that most of the population lives in these urban environments which are very dense. 

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust. 

The correct answer is kettles.