Explain why metal powder is used instead of large piece of metal

The surface area increases, thus increasing the rate of reaction

Explanation:

When you use powder instead of solid metal, the surface area to volume ratio increases and so does the rate of reaction, because the chance of collisions between the particles increases as they can "touch" the metal more easily when it is looser, like powder.

shield volcanos are angry and get mad over the smallest things so much that there heads erupt   pahoehoe and a'a lava. a composite volcano is the poller opposite of a shield volcano. its   peaceful thing and knows how to control its emotions.