Which age group shows the greatest difference between males and females?

Great question, let me try helping you on this one.

Well, it's not a secret that females, in general, live longer than males. This means that as people reach older age, males start dying few years earlier (of course, both genders die at different time; however, statistically saying, men do start dying earlier)

This leaves us with one possible answer - 75-80 years old since this is the average lifespan of a human being. 

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.