Let's look at lava

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1. READ/play the text
2. CLICK the picture (and video)
3. TRY this:

Q1: Why is the same lava sometimes yellow and sometimes black?

[Answer]

Lava is a curious substance that can be as runny as water or as sticky as treacle.

It can be black, brown, red, orange and yellow in color.

It can spread out like sheets, coil up like ropes or make a broken, moon-like landscape of blocks.

It all depends on how hot it is and what it's made from.