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This video might be great for teaching polarity and dissolving. We're going to show you how to make water-proof sand! It's fun, easy and awesome!

When you combine sand with a water-resistant chemical you create a hydrophobic substance that can clean up oil spills, give you awesome visuals, and quite possibly hours of fun.

Huw James took a trek up Mount Etna and decided to show us what actually happens when a volcano erupts!

With a little bit of help from Dr Suze Kundu and using a simple demonstration heating a glass beaker of wax, stone, sand and water we can see what happens when a volcano erupts.

We can actually tell a lot about a volcano looking at the lava that comes out. If the lava is quite dense and thick we know it contains a lot of the compound silica. If it is less dense it has less silica and spreads out a lot more.

Thick lava will generally erupt from one vent and follow one flow down the side of the volcano. Thinner lava, lava that is less dense, generally erupts from the surrounding magma chambers and flows in many different channels.

The first color pictures from the NASA space probe expedition to Mars have now been published. They look like -- well, they look like pictures of a lifeless, distant planet. They show blank, empty landscapes. They show craters and boulders. They show red sand. Death Valley, the most desolate of American deserts, at least contains strange cacti, vicious scorpions, the odd oasis. Mars has far less than that. Not only does the planet have no life, it has no air, no water, no warmth. The temperature on the Martian surface hardly rises much above zero degrees Fahrenheit, and can drop several hundred degrees below that.