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Holy Trinity CE Primary School

Holy Trinity CE Primary School

Learning and caring together, building a firm foundation for the future

Unbreakable Baggies?! That's Science!

We had another Super Science session this week.

Year 4 explored scientific language such as polymer, flexible and seal.  Having made predictions as to whether it is possible to pierce a bag full of water with a pencil without any leakage and therefore loss of its contents, the class set about investigating this.


Filling sandwich bags with coloured water, squeezing the air out and zipping them up.  Then the children stabbed sharp pencils through their bags and out the other side.

A chorus of excitement and bewilderment as they discovered that the theory was true.  For most part, no leakage.

What did we learn?

Bags are made of polymer, like chains of beads, they move when the pencil stabs and goes through the bag. The polymers then reposition themselves, sealing the pencils in the process.  Wow! 

Leaks were everywhere when the pencils were removed because the holes were permanent.

Well done Year 4!

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  • The school’s Christian values of love, honesty and respect are well expressed through its caring atmosphere. This impacts positively on the strong sense of belonging and supporting relationships evident across the school.

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