“The Unique Properties of Water” Multimodal Learning Please also refer to http://www.getwet.org.uk/primary-school-stories Film: 1. Dunkirk: Overview & Evaluation of GetWET project Year 1 for background and discussion of some of the activities shown here.
What is an experiment? You observe something…. You form a hypothesis (a forecast, based on your observation and/or on what you already know)…. You test the hypothesis through an experiment, with a ‘fair test’…. Write up what you discovered (what you expected, and/or what you didn’t).
Vocabulary: Hypothesis, atom, bonding, hydrogen bonding, molecule, freezing, melting point, solid, liquid, gas, condensation, evaporation, energy, expand, contract, collaborate, surface tension…
Start by inviting the children to explore the multi-sensory properties of water….
Water’s molecular structure
Attach 2 Jelly Tots to either side of a Fruit Pastille (like Mickey Mouse’s ears), to form a rough triangle... This models a water molecule. 2 Hydrogen atoms are bonding with 1 Oxygen atom, to make the H2O molecule… (The angle between the 2 hydrogen atoms, or Mickey’s ears, is 104.5degrees)… Don’t eat the sweets till the cocktail sticks have been removed!
Use PE/Dance to explore the 3 states of water: solid, liquid and gas in the following way…
Outside, warm the children up by running, walking, and standing still. Get everyone to shake hands, using one hand, then two. Ask the children to spread out, then stand very close together…
In groups of 3, ‘cast’ the children as 1 oxygen atom and 2 hydrogen twin atoms (PSHE – use, then mix up, the genders..... or avoid cliques!). The solo oxygen child holds a single hand of the 2 hydrogen children twins. This is the H2O molecule (like the sweet model above)…
Get the threesomes to walk around, joining up with other molecules (Hydrogen children grasp the back of an Oxygen child in another water molecule). Keep moving – this is like water…
Spread the children out & moving fast to replicate gas… The groups of 3 in a water molecule can stay together to represent water vapour
Slow them down to liquid water again…
Arrange them in a regular pattern to replicate solid water, i.e. ice…
In the hall later, repeat the exercise… Then use music with strong emotional and rhythmic content to encourage the threesomes to create mini dance dramas about people liking/disliking each other… This will reinforce their science learning (hydrogen bonding etc)
Surface Tension
How come certain things float on water?... Waterboatman, observation at Dunkirk Primary School pond How come certain things float on water?...
…And why doesn’t water run all over the place?
Because water molecules are more attracted to each other than they are to air, the molecules at the surface of the water are pulled/attracted down and sideways into the liquid… this stretches the molecules on the surface, causing surface tension.
This is what causes rain drops to be spheres, until gravity and air resistance turns them into ‘tear drops’ and pulls them out of shape as they fall…
You can test how surface tension works by dropping water from a small plastic pipette onto a shiny surface, like a white board.
Ask the children to write up what they observed, and suggest how this might be reflected elsewhere in the natural world…. Why do some surfaces (e.g. concrete) get wet, whilst others do not (e.g. drops of water on a plastic playground slide)?
A hydrophobic surface (plastic) will repel water A hydrophilic surface (concrete) will attract water and become wet
You can use detergent to show how water tension can be broken….
Sprinkle some pepper onto the surface of water in a glass jar….
Drop a little washing up liquid from a toothpick onto the surface of the peppery water….
Ask the children to draw and write up their observations of what happens ….
You can carefully place a paperclip on the surface water to show the effects of surface tension…. http://science.wonderhowto.com/how-to/make-paperclip-float-water- 0145901/ as example Break the surface tension with a drop of detergent, and the paperclip will sink