Question

ordering seafloor spreading
put the steps of seafloor spreading in order from first to last.
magma hardens.
rock moves outward.
magma pushes upward.
a crack forms.

Explanation:

Seafloor spreading begins with a crack forming in the oceanic crust. This allows magma (from the mantle) to push upward. As the magma reaches the surface, it cools and hardens to form new oceanic crust. Over time, the newly - formed rock (and the older rock adjacent to it) moves outward from the mid - ocean ridge (where the spreading occurs).

Answer:

1. A crack forms.
2. Magma pushes upward.
3. Magma hardens.
4. Rock moves outward.