As depth increases, the density of the layers decreases.
The best answer among the choices is option D. New substances are being formed will best explain that this process is a chemical change. Although, it cannot be seen directly we knew that an acid and base will undergo neutralization reaction forming a salt and water. The heat given off by the reaction can be a parameter however it does not only happens for reactions. It can also happen when dissolving substances.
Formation of mountains by one continental plate moving into another (Indian plate pushing north, forming the Himalayas)
Vocanoes from an oceanic plate being submerged beneath another plate and melting, causing liquid hot magma to rise to the surface
A, B, C, and D, because they are changing from a solid to a liquid, liquid to solid, and solid to gas. Phase changes are when a solid, liquid, or gas, turns into a solid, liquid, or gas. Ex. Ice melting is a solid changing into a liquid. Hope this helps!
