The convection going on with the magma in the asthenosphere
Chemical change is any change that results in the formation of new chemical substances. At the molecular level, chemical change involves making or breaking of bonds between atoms. These changes are chemical: iron rusting (iron oxide forms) gasoline burning (water vapor and carbon dioxide form)
In order to be considered a vector, a quantity must include Magnitude (A) and Direction (D).
-- If acceleration and velocity are in the same direction,
then the object is speeding up.
-- If acceleration and velocity are in opposite directions,
then the object is slowing down.
-- If acceleration is perpendicular to velocity, then the object
is moving on a circular curve at constant speed.