Explain ridge push and slab pull as a cause of plate movement.

Ridge push magma rises as the plates move apart. The magma cools to form new plate material. As it cools It becomes denser and slides down away from the ridge. This causes other plates to move away from each other.
Slab pull – The denser plate sinks back into the mantle under the influence of gravity. It pulls the rest of the plate along behind it.