GCSE · A-level · Oxbridge interviews · UCAT
Revision that teaches you to think.
Every other tool will hand your child the answer. Bluebell asks the next question instead — the way a good tutor does, until the understanding is theirs.
24/7 access · From £5.99 a month · AQA, Edexcel & OCR
It has the answer. It guides you to it.
A student who already knows the fact still gets asked the next question. Say you don’t know and it finds you a smaller foothold rather than caving. What you leave with is understanding, not something to copy.
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Bluebell
Almost every substance is denser as a solid than as a liquid. Water is not. Why?
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Student
Because ice is less dense than water.
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Bluebell
That’s the observation, not the reason. Why is it less dense?
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Student
Hydrogen bonding?
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Bluebell
Hydrogen bonds are strong — and stronger forces usually make a solid denser. So why not here?
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Student
I don’t know.
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Bluebell
Then try this. In almost every solid, each particle touches eight or twelve neighbours. In ice, each water touches exactly four. Why would it settle for four?
Every question above is a step towards the answer. None of them is the answer.