2.4.3: Bubble Raft

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A bubble raft can be made by bubbling air through a soap solution, using a small air pump connected to a hollow needle. The size of the bubbles can be controlled by varying the flow of air through the needle, and by varying the depth below the surface of the liquid that the needle is submerged. Two bars at each end allow forces to be applied to the bubble raft.

Creating the bubble raft.

Examine the following still photograph of the bubble raft. The bubbles have been arranged approximately into a single crystal using gentle movement of the bars. The raft shows several defects that are analogous to crystalline defects. Try and identify vacancies, dislocations, substitutional solutes and interstitial solutes.

Example \(\PageIndex{1}\)

There is at least one example of a vacancy, a dislocation, a substitutional solute and an interstitial solute in this bubble raft.

Solution

A vacancy, dislocation, substitutional solute and interstitial solute identified.