Wonderful World of Science

Here are some practical science ideas for you to have a look at. Remember to comment on the blog/google classroom when you have made either of them.

Chromatography Butterflies

Equipment: filter paper/a circle of craft paper, felt tips, glass of water, pipe cleaners.

How to: using a felt tip, draw a single-line circle around the middle of the filter paper; only use one colour; fold the circle into a cone shape; place the cone in the glass so that it is just touching the water; what happens as the paper absorbs the water?  After a couple of hours, lie the paper out to dry, then use a pipe cleaner to scrunch the middle together and create a butterfly shape.

What is happening? Chromatography is a technique for separating mixtures. Here, the ink of the felt-tip (the sample) is put on the paper (the stationary phase) and the water then moves up the paper (the mobile phase). The different pigments of the ink have different properties (more/less soluble etc) which means they travel at different speeds and separate.

Taking it further: children could explore different felt tip colours, different sizes of circles or different sizes and types of paper. They could also use rulers to measure the distance travelled by the different colours.

 Make your own lava lamp

Equipment: empty plastic bottle, water, oil, food colouring, effervescent tablet.

How to: fill a third of the bottle with water; fill another third with oil; add 10 drops of food colouring; watch how the different liquids settle – what do you notice? Break the tablet in half and add it to the bottle. What happens? Add the remaining half table to continue the results.

What is happening? The oil sits on top of the water because the oil is lighter than the water or, more specifically, less dense than water. When the tablet is added it sinks to the bottom and starts dissolving in the water, creating a gas. As the gas bubbles rise, they take the coloured water with them. When the bubbles of coloured water reach the top, the gas escapes and the coloured water sinks down through the oil.

Taking it further: children could explore what happens if they put the lid on the bottle when the lava lamp is working, whether different oils and food colourings create different effects and whether the ratios of water to oil make a difference.

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