Science of Healthy Skin: Investigating what happens when oil is added to water

Full details of the activity can be found in the CIEC resource 'Science of Healthy Skin’ which can be downloaded from: http://www.ciec.org.uk/resources/science-of-healthy-skin.html

Based upon the extraction of lanolin from wool grease, the activities in this resource include testing immiscible liquids using oil and water and investigating the effects of adding detergent to produce emulsions which in turn reduce the efficiency of the separation of oil from water.

The Activity: Fleece to Grease

Resources 

• 300 ml water
• 300 ml sunflower oil
• 50 ml clear water - sample A
• 50ml clear glycerine - sample B
• 50 ml clear detergent - sample C
• 50 ml white vinegar - sample D
• 4 clear plastic mini pop bottles or lidded containers around 30ml per group of 4 children
• Pipette x 1 for each child
• Teaspoon or similar for stirring
• 100 ml measuring cylinder 

Objectives

• To describe changes that occur when materials are mixed
• To make systematic observations and measurements
• To know that that some liquids do not mix, can be separated easily and are termed ‘immiscible’
• To observe that detergent can cause immiscible liquids to mix, producing an emulsion

What happens when oil is added to water?

Each child in the team of 4 to pour 10ml of water and 10ml of oil into one of the containers.

Ask them to wait for 1 minute to see what happens to the oil and water.

Tip the containers upside down four times and ask the children .....

• Did the oil and water mix?
• Did shaking make the liquids mix?
• Why do you think this happened?

The oil and mixture quickly separate when they are on their own.  But will adding any of the other ingredients make a difference?

Investigate whether adding sample A, B, C or D affects the separation of water and oil.

Using the pipette, add 10 drops of sample A to one of the bottles, 10 drops of sample, B to another bottle and 10 drops of samples C and D to the other two bottles.

Ask children to observe how long it takes for the oil and water to separate after 4 shakes.

Ask them to consider how they will record their observations.

Health and Safety

Remind the children not to drink their samples.

Links to the National Curriculum for Science:

Working Scientifically

Learning Objectives

• planning different types of scientific enquiries to answer questions, including recognising and controlling variables where necessary
• Taking measurements, using a range of scientific equipment, with increasing accuracy and precision, taking repeat readings when appropriate
• Use observations, measurements or other data to draw conclusions

Subject Knowledge

Learning Objectives

• Know that changes occur when materials are mixed and some of these are reversible

Thinking, Doing, Talking Science

CIEC has recently been involved in the latest trial of a flagship professional development programme in science teaching – Thinking, Doing, Talking Science (TDTS).  TDTS aims to support teachers to make science lessons in primary schools more practical, creative and challenging - with a focus on the development of higher order thinking skills. It does this by giving them lots of ideas for engaging practical lessons combined with strategies which provoke reasoning and creative thinking.

One of these strategies is called PMI (plus, minus, interesting).  Teachers suggest a scenario to children and then invite them to work in small groups to think of all of the positives that they can about the scenario.  They are then asked to think about all of the possible draw backs, or negatives, of the same scenario.  Finally, they are asked to think of any interesting questions or thoughts that the discussion have given rise to.

One possible PMI question is What if we lived in a world without gravity?  

(picture sourced from pixabay)           

Well, for one thing, there’d no longer be a market for helium filled balloons! PMI is such a successful strategy because there are no right or wrong answers and this gives children the confidence to contribute their thoughts and ideas.  However, the children will use, and reveal, a lot of their scientific understanding as they take part in the discussion.  As well as giving teachers a valuable assessment opportunity the discussion can help to move children’s thinking forward as they explore their ideas together.

TDTS has been developed by Science Oxford and Oxford Brooks University and initial trials have shown that it has the potential to increase children’s engagement with and attainment in science, especially for vulnerable groups of pupils.  The impact has not been so marked with the roll out stage of the trial.  Nevertheless, results are promising enough that the EEF are continuing to fund trials of this low-cost intervention as “the available evidence indicates that the programme can be implemented at scale through a train-the-trainers model, that it is valued by teachers exposed to the programme, and it changes their teaching practices in a manner consistent with the hypothesis.”  CIECs Nicky Waller will be continuing to work with the core team during this next stage of the pilot.

Teachers on one of the TDTS training days in Lincolnshire

Feedback from teachers has been very positive.  After attending the training with CIEC one of the teachers from a Lincolnshire school wrote

“My head teacher thoroughly loves the new way of teaching science that I am doing since coming on the course, she loves the way the children have such high level thinking, the questions they asked and the previous lessons that they were drawing up on. So thank you for giving me knowledge and inspiring me to teach science in a completely different way!"

For more information on the TDTS project, go to https://scienceoxford.com/thinking-doing-talking-science/