Answer:
The correct answer is "brittle".
Step-by-step explanation:
A sample of iodine is easiest to ship as a powder because it is "brittle", making it easy to break into small pieces. Brittle is a characteristic of substances that are hard and dry, which makes them liable to break or shatter easily. Iodine is a substance that is brittle because in its solid state, the particle experience strong electrostatic attractions, which makes them very volatile.