Bottle-Top Volcano

Stand the empty bottle in the middle of the cardboard base.

Scrunch sheets of newspaper into balls and pack them around the bottle to build a mountain shape, keeping the bottle opening clear at the top.

Tape the newspaper firmly to the base and to itself so the mountain holds together.

Cover the mountain with card or paper strips and tape them down to make a smooth surface.

Paint the mountain brown or grey and leave it somewhere safe to dry completely.

Stand the finished volcano on a tray or take it outdoors, then spoon 3 tablespoons of baking soda into the bottle.

Add a good squirt of washing-up liquid and a few drops of red food colouring on top of the powder.

When you are ready to erupt, pour in the vinegar quickly, step back, and watch the foamy lava whoosh out. If it fizzes only a little, add another spoon of baking soda first, then more vinegar.