Galilee said that if you rolled a ball along a level surface it would be

Which best describes how fluids change as they travel through different portions of the convection currents? they change to solids at the outer portion of the convection currents. they change to solids at the inner portion of the convection currents. they become more dense at the outer portion of the convection currents. they become more dense at the inner portion of the convection currents

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.

An atom that has gained or lost electrons is called an _