Effects of pressure on an air bubble

[studentmom]

Homework Statement

an air bubble originating from a scuba diver at a depth of 18.0m has a diameter of 1.0cm. What will be the bubble's diameter when it reaches the surface?
assume constant temperature

Homework Equations

I'm not sure what equation to use for this...

The Attempt at a Solution

I know that an increase in pressure should have an effect on the size of the air bubble. But I don't know where to start.

 

[interested_learner]

What is the pressure inside the bubbles? What is pressure outside the bubbles? Are they the same? Different? How does the pressure inside the bubbles relate to bubble size? Given a set number of molecules in the bubble, will a higher pressure bubble have a smaller volume or a larger volume?

Answer those questions and you will have your answer.