If there is no compositional difference between two oceanic ...

[sarasara]

If there is no compositional difference between two oceanic plates, what other factor will determine which plate will become the subducted one and why? (What other factor can control density?)
 
  What will be an ideal response?

Question 2

If new plate material is being created at divergent plate boundaries, is the Earth growing larger? Explain why or why not.
 
  What will be an ideal response?

[djofnc]

Answer to Question 1

Answer: Temperature, which is a function of age. - Colder plates are denser and therefore will become the subducted plate.

Answer to Question 2

Answer: No. The Earth is remaining the same size because although new plate material is being created, old plate material is being destroyed at convergent boundaries.

[sarasara]

Excellent

[xoxo123]

Thanks for the timely response, appreciate it