When gas escapes quickly and violently from lava it may produce a frothy glass full of holes left by former gas bubbles;this porous material,known as pumice,contains so many holes it can float on water.

Question

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This statement is true. Pumice is a volcanic rock that is formed by the quick and violent escape of gas from lava, creating a frothy texture full of holes from former gas bubbles. It is so porous that it can float on water.

When Gas Escapes Quickly and Violently from Lava It May