Hawaiian volcanoes produce two types of the same variety of lava. Pahoehoe is smooth and ropy; aa is chunky. Formulate a hypothesis as to why the same lava can have two different appearances.

I will explain.

Explanation:

Lava comes in two primary appearances: Pahoehoe and aa. The reason why they have two different types of appearances is because the older aa in the photo has weathered and the iron in it has oxided somewhat, giving it a reddish and chunky appearance. It also moves fast. Pahoehoe has a flow that is comparatively smooth or a "ropy" surface. Pahoehoe doesn't have the chunky appearance.